A German YouTuber said he made it onto the field during the European Championship opening ceremony while disguised in a mascot costume, in an incident which revealed flaws in tournament security.

Marvin Wildhage published a video appearing to show how he entered the Munich stadium last Friday in a fake costume and danced on the corner of the field before being led away by a UEFA staff member.

UEFA said in a statement, "We can confirm that there was an incident with a fake mascot costume at the match in Munich ... between Germany and Scotland. Three people have gained unauthorised access.

"UEFA has assessed the situation and initiated the necessary organisational measures. Three individuals have been banned from entering stadiums hosting UEFA Euro 2024 matches. Please understand that we cannot provide any further information due to the ongoing proceedings of the investigating authorities."

Wildhage said he ordered his bear costume online from China for 3,200 ($3,400) and made his own fake tournament credentials by copying the design from photos posted on social media by Euro 2024 employees.

The credentials didn't pass a scan at the entrance to Allianz Arena but Wildhage and an associate were waved in by a security guard who was convinced by an imitation parking pass, according to the account shown in the video.

Wildhage said he was eventually detained by security after appearing at the opening ceremony, and he was held in a detention arena within the arena before being released long after Germany's 5-1 win over Scotland finished.

It wasn't the first time Wildhage flagged up security gaps around the tournament. In an earlier video, he entered the field dressed as a player at a Germany training session last month.

The tournament draw in December was also interrupted when moaning noises were played at the ceremony at a Hamburg concert call. A British prankster said he planted a cell phone on site and made calls to it to activate a ring tone.