A policeman in Sweden seized a fugitive criminal on Friday evening while both were naked in a sauna, after stumbling upon him by chance.

The officer was visiting the sauna, which is known in Sweden as a 'bastu', on his day off.

He soon realised that one of the men sweating next to him in the crowded room was a convicted criminal who was on the run after being sentenced to jail for drugs offences.

"By a coincidence, and in way that is quite comic, they both recognised each other in the sauna," Christoffer Bohman, deputy police chief in the Stockholm district of Rinkeby, told Sweden's state broadcaster SVT.

As the wanted man had also been found guilty of attempting to assault a public servant, the arrest was potentially dangerous.

"It's easier to take action when you have your colleagues with you, and all your tools and equipment," Mr Bohman said.

"This was as stripped-down as it gets, and in more ways than one."

The officer was saluted in a post on the Rinkeby Police's Facebook page under the headline, "Naked Arrest".

"To our dear colleague who kept your head cool when it was heating up to a potentially dangerous situation, despite being on your day off and relaxing in a spa," the post reads.