
The midfielder has issued an apology and withdrawn from the national squad following the announcement of the probe by Lucerne prosecutors.
AI-generated summary
In 2022, Switzerland required Covid-19 vaccination certificates for travel and access to various venues. These measures were in place until the spring of 2022.
Switzerland captain Granit Xhaka is under investigation by Swiss prosecutors over allegations he obtained a forged Covid-19 vaccination certificate.
The 33-year-old is alleged to have obtained the certificate in 2022, when it was a requirement in Switzerland for some travel abroad.
The public prosecutor's office of the city of Lucerne confirmed the investigation was under way to determine whether any criminal behaviour took place in obtaining a "false or forged" certificate.
The Sunderland midfielder, who was playing for Arsenal at the time, posted a statement on social media on Monday saying he had a "mistrust" towards the vaccine and had been "influenced by worries and uncertainty".
He said: "In this troubled state of mind I acquired a vaccine certificate, instead of clarifying my unanswered questions in the proper way.
"Today I see clearly, that this way was not correct. It was a mistake. I'm sorry.
"I take responsibility for this decision, will engage with the process of establishing the facts and fully co-operate with the relevant authorities."
The Swiss office of public health confirmed that while there was never a general legal requirement to obtain or hold such a certificate, it was needed for access to various activities, venues and travel, meaning that participation was restricted for anyone who did not possess one.
These measures in Switzerland were in place until spring 2022. After that point, Covid-19 certificates continued to be issued, primarily to enable members of the public to meet entry requirements when travelling abroad.
The Swiss Football Association said Xhaka, the country's record appearance holder with 152 caps, had withdrawn from the Swiss camp for their upcoming Nations League matches against Scotland, North Macedonia and Slovenia following his statement.
It added the decision to withdraw had been made jointly by the player and management and that they would discuss Xhaka's future with the team after the international window.
Switzerland have away fixtures against North Macedonia and Scotland on 26 and 29 September, before facing Slovenia and North Macedonia at home in early October.
Sunderland boss Regis le Bris refused to comment on the allegations following the Black Cats' defeat at Manchester City on Sunday.
"It is not my area to speak about those problems or situations," he said. "My area is football. About football, he is really good."
Xhaka captained Switzerland at the World Cup earlier this year, where they were knocked out in the quarter-finals by eventual runners-up Argentina.
AI outlook — possibilities, not facts
Swiss authorities will continue the investigation into the certificate's origin.
Very likely · Within months

Great Britain was defeated by the Czech Republic in the Billie Jean King Cup quarter-finals as Sonay Kartal and Katie Boulter lost their singles matches. Kartal lost a three-hour marathon to Marie Bouzkova, while Boulter was beaten by Wimbledon champion Linda Noskova. The loss marks Britain's first failure to reach the semi-finals since 2023.

La Liga president Javier Tebas has rejected claims of a refereeing conspiracy against Real Madrid, calling the narrative an excuse for poor performance. This follows manager Jose Mourinho's public criticism of officiating after a 2-1 loss to Atletico Madrid.

Mikel Arteta has reached a final agreement to extend his contract as manager of Premier League club Arsenal. The deal, which includes a significant salary increase, ensures his tenure at the Emirates Stadium will extend beyond his current season expiration.

Henry Pollock has ended contract speculation by signing a contract extension with Premiership champions Northampton, describing the decision as very easy.

BBC Sport offers a daily football quiz where users guess footballers using clues, with points awarded based on the number of attempts needed to identify the correct player, as set by Joe Rindl.

The Los Angeles Rams defeated the New York Giants 28-6 on Monday night, with Davante Adams recording eight catches for 195 yards and two touchdowns, and Aaron Donald making his first NFL appearance in 32 months with three tackles. Matthew Stafford threw for 327 yards and four touchdowns, moving into sixth place in NFL history for career touchdown passes.