MP Simon Danczuk was arrested in Spain following an alleged incident with his estranged wife, the BBC understands.
The 49-year-old spent two nights in a police cell in Alicante following a loud row with wife Karen Danczuk.
The Rochdale MP was suspended by the Labour Party in December after he admitted sending lewd texts to a 17-year-old girl.
Mr Danczuk, who is separated from his wife Karen, was later released without charge, Spanish police said.
The Foreign Office said it was providing support to a British man detained by police in Spain.
The Labour Party refused to comment.