Police are investigating a potential breach of coronavirus regulations after footage of Neil Lennon emerged online.
The Lurgan-born former Celtic boss lives in Glasgow, but was filmed in the Halston Hotel in Carlisle, Cumbria, on Tuesday night, The Sun reported.
Beer gardens in England had opened the day before, although they remain closed in Scotland.
Currently, people in Scotland cannot travel outside their local authority area, unless it is essential.
A spokesman for Cumbria Police said: "The matter is being investigated to ascertain whether any breach of coronavirus regulations has taken place.
"It would be inappropriate to comment further whilst this investigation takes place."
A spokesman for Lennon declined to comment.
Travel remains restricted in Scotland and journeys will only be allowed to other parts of Britain from April 26, with reviews planned on journeys to Northern Ireland and the Republic.
Earlier, Rangers legend Ally McCoist leapt to the defence of 47-year-old Lennon, after the video surfaced. The former Northern Ireland international recently resigned as manager of Celtic.
Branding the video an "invasion of his privacy" and calling those behind it a "disgrace", 58-year-old McCoist said it "shouldn't be allowed".
He told talkSport Radio: "I have been there so I'm not going to preach to anybody about it, but what I will say is I think the invasion of his privacy is a disgrace.
"I find stuff like this disgusting. We don't know what state they're in and how vulnerable they feel." The former Rangers rival added that camera phones allowed people on social media to "take absolute liberties", branding them "one of the worst inventions in the world".
"It is a scandal. I just find it unbelievable that anybody in a situation where somebody needs help would film it rather than help. What's that all about?" he added.
Users on social media were quick to condemn the video, with fans on both sides of the traditionally hostile Old Firm rivalry slamming those behind the video.
Crystal palace winger Andros Townsend said: "Videos like that is where you kind of lose faith in fellow mankind. Some re-tweets, some likes."