diff --git a/src/Console/DatabaseStructure.php b/src/Console/DatabaseStructure.php
index a79e3a622..652abfd97 100644
--- a/src/Console/DatabaseStructure.php
+++ b/src/Console/DatabaseStructure.php
@@ -52,7 +52,7 @@ Usage
 
 Commands
     drop     Show tables that aren't in use by Friendica anymore and can be dropped
-       -e|--execute    Execute the dropping
+       -e|--execute    Execute the removal
 
     update   Update database schema
        -f|--force      Force the update command (Even if the database structure matches)
diff --git a/src/Console/MergeContacts.php b/src/Console/MergeContacts.php
new file mode 100644
index 000000000..79cd0b4b7
--- /dev/null
+++ b/src/Console/MergeContacts.php
@@ -0,0 +1,165 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2022, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Console;
+
+use Friendica\Core\L10n;
+use Friendica\Database\Database;
+
+/**
+ * tool to find and merge duplicated contact entries.
+ */
+class MergeContacts extends \Asika\SimpleConsole\Console
+{
+	protected $helpOptions = ['h', 'help', '?'];
+
+	/**
+	 * @var $dba Database
+	 */
+	private $dba;
+
+	/**
+	 * @var L10n
+	 */
+	private $l10n;
+
+	protected function getHelp()
+	{
+		$help = <<<HELP
+console mergecontacts - Merge duplicated contact entries
+Synopsis
+	bin/console mergecontacts
+
+Description
+	bin/console mergecontacts
+		Remove duplicated contact entries
+
+Options
+	-h|--help|-? Show help information
+	-e|--execute Execute the merge
+HELP;
+		return $help;
+	}
+
+	public function __construct(Database $dba, L10n $l10n, array $argv = null)
+	{
+		parent::__construct($argv);
+
+		$this->dba  = $dba;
+		$this->l10n = $l10n;
+	}
+
+	protected function doExecute()
+	{
+		$duplicates = $this->dba->p("SELECT COUNT(*) AS `total`, `uri-id`, MAX(`url`) AS `url` FROM `contact` WHERE `uid` = 0 GROUP BY `uri-id` HAVING total > 1");
+		while ($duplicate = $this->dba->fetch($duplicates)) {
+			$this->out($this->l10n->t('%d %s, %d duplicates.', $duplicate['uri-id'], $duplicate['url'], $duplicate['total']));
+			if ($this->getOption(['e', 'execute'], false)) {
+				$this->mergeContacts($duplicate['uri-id']);
+			}
+		}
+		return 0;
+	}
+
+	private function mergeContacts(int $uriid)
+	{
+		$first = $this->dba->selectFirst('contact', ['id', 'nurl', 'url'], ["`uri-id` = ? AND `nurl` != ? AND `url` != ?", $uriid, '', ''], ['order' => ['id']]);
+		if (empty($first)) {
+			$this->err($this->l10n->t('No valid first countact found for uri-id %d.', $uriid));
+			return;
+		}
+		$this->out($first['url']);
+
+		$duplicates = $this->dba->select('contact', ['id', 'nurl', 'url'], ['uri-id' => $uriid]);
+		while ($duplicate = $this->dba->fetch($duplicates)) {
+			if ($first['id'] == $duplicate['id']) {
+				continue;
+			}
+			if ($first['url'] != $duplicate['url']) {
+				$this->err($this->l10n->t('Wrong duplicate found for uri-id %d in %d (url: %s != %s).', $uriid, $duplicate['id'], $first['url'], $duplicate['url']));
+				continue;
+			}
+			if ($first['nurl'] != $duplicate['nurl']) {
+				$this->err($this->l10n->t('Wrong duplicate found for uri-id %d in %d (nurl: %s != %s).', $uriid, $duplicate['id'], $first['nurl'], $duplicate['nurl']));
+				continue;
+			}
+			$this->out($duplicate['id'] . "\t" . $duplicate['url']);
+			$this->mergeContactInTables($duplicate['id'], $first['id']);
+		}
+	}
+
+	private function mergeContactInTables(int $from, int $to)
+	{
+		$this->out($from . "\t=> " . $to);
+
+		foreach (['post', 'post-thread', 'post-thread-user', 'post-user'] as $table) {
+			foreach (['author-id', 'causer-id', 'owner-id'] as $field) {
+				$this->updateTable($table, $field, $from, $to, false);
+			}
+		}
+
+		$this->updateTable('contact-relation', 'cid', $from, $to, true);
+		$this->updateTable('contact-relation', 'relation-cid', $from, $to, true);
+		$this->updateTable('event', 'cid', $from, $to, false);
+		$this->updateTable('fsuggest', 'cid', $from, $to, false);
+		$this->updateTable('group', 'cid', $from, $to, false);
+		$this->updateTable('group_member', 'contact-id', $from, $to, true);
+		$this->updateTable('intro', 'contact-id', $from, $to, false);
+		$this->updateTable('intro', 'suggest-cid', $from, $to, false);
+		$this->updateTable('mail', 'author-id', $from, $to, false);
+		$this->updateTable('mail', 'contact-id', $from, $to, false);
+		$this->updateTable('notification', 'actor-id', $from, $to, false);
+		$this->updateTable('photo', 'contact-id', $from, $to, false);
+		$this->updateTable('post-tag', 'cid', $from, $to, true);
+		$this->updateTable('post-user', 'contact-id', $from, $to, false);
+		$this->updateTable('post-thread-user', 'contact-id', $from, $to, false);
+		$this->updateTable('user-contact', 'cid', $from, $to, true);
+
+		if (!$this->dba->delete('contact', ['id' => $from])) {
+			$this->err($this->l10n->t('Deletion of id %d failed', $from));
+		} else {
+			$this->out($this->l10n->t('Deletion of id %d was successful', $from));
+		}
+	}
+
+	private function updateTable(string $table, string $field, int $from, int $to, bool $in_unique_key)
+	{
+		$this->out($this->l10n->t('Updating "%s" in "%s" from %d to %d', $field, $table, $from, $to), false);
+		if ($this->dba->exists($table, [$field => $from])) {
+			$this->out($this->l10n->t(' - found'), false);
+			if ($in_unique_key) {
+				$params = ['ignore' => true];
+			} else {
+				$params = [];
+			}
+			if (!$this->dba->update($table, [$field => $to], [$field => $from], [], $params)) {
+				$this->out($this->l10n->t(' - failed'), false);
+			} else {
+				$this->out($this->l10n->t(' - success'), false);
+			}
+			if ($in_unique_key && $this->dba->exists($table, [$field => $from])) {
+				$this->dba->delete($table, [$field => $from]);
+				$this->out($this->l10n->t(' - deleted'), false);
+			}
+		}
+		$this->out($this->l10n->t(' - done'));
+	}
+}
diff --git a/src/Core/Console.php b/src/Core/Console.php
index be5f31598..ebd4c51a9 100644
--- a/src/Core/Console.php
+++ b/src/Core/Console.php
@@ -60,6 +60,7 @@ Commands:
 	lock                   Edit site locks
 	maintenance            Set maintenance mode for this node
 	movetoavatarcache      Move cached avatars to the file based avatar cache
+	mergecontacts          Merge duplicated contact entries
 	user                   User management
 	php2po                 Generate a messages.po file from a strings.php file
 	po2php                 Generate a strings.php file from a messages.po file
@@ -93,6 +94,7 @@ HELP;
 		'globalcommunitysilence' => Friendica\Console\GlobalCommunitySilence::class,
 		'lock'                   => Friendica\Console\Lock::class,
 		'maintenance'            => Friendica\Console\Maintenance::class,
+		'mergecontacts'          => Friendica\Console\MergeContacts::class,
 		'movetoavatarcache'      => Friendica\Console\MoveToAvatarCache::class,
 		'php2po'                 => Friendica\Console\PhpToPo::class,
 		'postupdate'             => Friendica\Console\PostUpdate::class,
diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index b72cc632a..a0eb1c3ec 100644
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -422,13 +422,14 @@ class DBA
 	 * @param array         $fields     contains the fields that are updated
 	 * @param array         $condition  condition array with the key values
 	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate, false = don't update identical fields)
+	 * @param array         $params     Parameters: "ignore" If set to "true" then the update is done with the ignore parameter
 	 *
 	 * @return boolean was the update successfull?
 	 * @throws \Exception
 	 */
-	public static function update($table, $fields, $condition, $old_fields = [])
+	public static function update($table, $fields, $condition, $old_fields = [], $params = [])
 	{
-		return DI::dba()->update($table, $fields, $condition, $old_fields);
+		return DI::dba()->update($table, $fields, $condition, $old_fields, $params);
 	}
 
 	/**
diff --git a/src/Database/Database.php b/src/Database/Database.php
index 41733f5f9..671425f9d 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -1284,11 +1284,12 @@ class Database
 	 * @param array         $fields     contains the fields that are updated
 	 * @param array         $condition  condition array with the key values
 	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate, false = don't update identical fields)
+	 * @param array         $params     Parameters: "ignore" If set to "true" then the update is done with the ignore parameter
 	 *
 	 * @return boolean was the update successfull?
 	 * @throws \Exception
 	 */
-	public function update($table, $fields, $condition, $old_fields = [])
+	public function update($table, $fields, $condition, $old_fields = [], $params = [])
 	{
 		if (empty($table) || empty($fields) || empty($condition)) {
 			$this->logger->info('Table, fields and condition have to be set');
@@ -1325,7 +1326,13 @@ class Database
 
 		$condition_string = DBA::buildCondition($condition);
 
-		$sql = "UPDATE " . $table_string . " SET "
+		if (!empty($params['ignore'])) {
+			$ignore = 'IGNORE ';
+		} else {
+			$ignore = '';
+		}
+
+		$sql = "UPDATE " . $ignore . $table_string . " SET "
 			. implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
 			. $condition_string;
 
diff --git a/view/lang/C/messages.po b/view/lang/C/messages.po
index 777b01160..5fbaeeacc 100644
--- a/view/lang/C/messages.po
+++ b/view/lang/C/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: 2022.05-rc\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2022-05-31 13:27+0000\n"
+"POT-Creation-Date: 2022-06-01 22:09+0000\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -1641,6 +1641,61 @@ msgstr ""
 msgid "The contact has been blocked from the node"
 msgstr ""
 
+#: src/Console/MergeContacts.php:74
+#, php-format
+msgid "%d %s, %d duplicates."
+msgstr ""
+
+#: src/Console/MergeContacts.php:86
+#, php-format
+msgid "No valid first countact found for uri-id %d."
+msgstr ""
+
+#: src/Console/MergeContacts.php:97
+#, php-format
+msgid "Wrong duplicate found for uri-id %d in %d (url: %s != %s)."
+msgstr ""
+
+#: src/Console/MergeContacts.php:101
+#, php-format
+msgid "Wrong duplicate found for uri-id %d in %d (nurl: %s != %s)."
+msgstr ""
+
+#: src/Console/MergeContacts.php:137
+#, php-format
+msgid "Deletion of id %d failed"
+msgstr ""
+
+#: src/Console/MergeContacts.php:139
+#, php-format
+msgid "Deletion of id %d was successful"
+msgstr ""
+
+#: src/Console/MergeContacts.php:145
+#, php-format
+msgid "Updating \"%s\" in \"%s\" from %d to %d"
+msgstr ""
+
+#: src/Console/MergeContacts.php:147
+msgid " - found"
+msgstr ""
+
+#: src/Console/MergeContacts.php:154
+msgid " - failed"
+msgstr ""
+
+#: src/Console/MergeContacts.php:156
+msgid " - success"
+msgstr ""
+
+#: src/Console/MergeContacts.php:160
+msgid " - deleted"
+msgstr ""
+
+#: src/Console/MergeContacts.php:163
+msgid " - done"
+msgstr ""
+
 #: src/Console/MoveToAvatarCache.php:91
 msgid "The avatar cache needs to be enabled to use this command."
 msgstr ""