Sunderland officials have launched an investigation after three players were alleged to have taken part in a filmed sex session.
Irish midfielder Liam Lawrence, goalkeeper Ben Alnwick and striker Chris Brown are reported to have appeared in the film with a mystery woman.
The players can expect to be in trouble with chairman Niall Quinn and manager Roy Keane if they are found to have breached the club's disciplinary rules.
Sunderland marketing and communications director Lesley Callaghan, speaking on behalf of the Board, said: 'The behaviour of any individual that adversely affects the image or good name of Sunderland Football Club is obviously disappointing, and we will be handling this matter internally.'
Lawrence, 24, is currently on loan at Stoke City with a view to completing a permanent move, while 19-year-old Alnwick has agreed to join Tottenham Hotspur in a £1million switch in January.
Brown, 21, remains part of Keane's squad, but has not been involved in the last three games.
Former Sunderland midfielder Martin Woods, 20, now with Rotherham United, is also reported to have been present when the filming took place at a flat.
