Granit Xhaka, the Sunderland midfielder and captain, has admitted to forging a Covid-19 vaccination certificate.

Xhaka has apologised for what he described as a “mistake” made in a “state of emotional turmoil”, and has been left out of Switzerland’s squad for the upcoming internationals.

According to a report from Blick, an outlet in Xhaka’s native Switzerland, over the weekend, the Lucerne public prosecutor’s office has opened proceedings against the national team captain, who is expected to be questioned in early October.

Reports from Switzerland state the forgery took place in 2022, when Xhaka was playing for Arsenal. The 33-year-old wrote on Instagram on Monday morning that he “felt a deep mistrust of the vaccine” and was “personally very unsettled”.

He added: “Over the last few days, there has been a great deal of media coverage regarding a matter from my past. I would like to comment on this personally.

“At the time, I was personally very unsettled and had serious reservations about the Covid-19 vaccination. I felt a deep mistrust of the vaccine and was overcome by fears and uncertainty.

“In this state of emotional turmoil, I obtained a vaccination certificate instead of seeking answers to my unresolved questions through the proper channels.

“Today, I can clearly see that this was not the right course of action. It was a mistake. I am sorry.

“I take full responsibility for this decision, am prepared to address the matter fully and will cooperate fully with the relevant authorities.”