Manchester United say captain Harry Maguire is “fully cooperating” with Greek authorities after reports he was arrested on the island of Mykonos.
Local media are reporting the England footballer, 27, was arrested following an alleged fight on Thursday night.
Two other Britons were also detained, according to the local reports.
Manchester United said in a statement: “The club is aware of an alleged incident involving Harry Maguire in Mykonos last night.
“Contact has been made with Harry, and he is fully co-operating with the Greek authorities.
“At this time we will be making no further comment.”
Maguire’s fiancee, Fern Hawkins, posted a picture of the pair in Mykonos on her Instagram page on Thursday night.
The couple have two baby daughters, the youngest of which was born in May.
Maguire went to Greece following United’s semi-final defeat to Sevilla in the Europa League on Sunday.
The club’s next competitive fixture is scheduled for 19 September, when they are due to open their 2020/21 Premier League campaign against Crystal Palace.
Sheffield-born Maguire became the world’s most expensive defender when he signed for United from Leicester City for an £80m transfer fee in August last year.
He has made 26 appearances for England and was a key part of the Three Lions run to the World Cup semi-finals in 2018.