Sunderland have said a tweet posted about new signing Kyle Lafferty which referred to loyalist flute bands was a “genuine mistake”.
The post, which captioned photos of the 32-year-old with the message “he’s seven foot and plays the flute”, was posted by the club on Monday.
The line references a chant which dates from Lafferty’s time with Scottish side Rangers and was swiftly deleted.
“It was a genuine mistake and was removed immediately,” the club said.
The Daily Record also reported that the club said: “It was written in all innocence by someone unaware of how it could be interpreted.”
The Northern Ireland international joined the Black Cats on a deal until the end of the season on Friday having last featured for Norwegian club Sarpsborg 08.
He has also played for Hearts, Burnley and Norwich.