A second-string goalkeeper for English premier league champions Arsenal has been arrested and bailed in connection with a sexual assault investigation in London, police sources said on Monday.

A police spokeswoman said two 22-year-olds had been arrested and bailed in connection with an allegation of sexual assault in the early hours of last Wednesday.

A source identified one of the men as Arsenal goalkeeper Graham Stack, who is on loan to Millwall for the season.

Arsenal declined to comment and no one at Millwall was immediately available for comment.