A 35-year-old man has been arrested on suspicion of murdering a 37-year-old Lancashire businessman missing for nearly two weeks.
Police say Mr Guilfoyle had a criminal background
Three men and a woman who were arrested have been released without charge.
David Guilfoyle, an international pool player with a criminal past, has not been seen since watching the Champions League final in a pub on 25 May.
Police said Mr Guilfoyle may have been assaulted at his bungalow in Royds Avenue, Accrington.
The newly arrested man and the four people freed were all from the Accrington area.
Mr Guilfoyle, who was last seen leaving the Grey horse pub in Whalley Road, has criminal convictions for smuggling cigarettes and possessing fake bank notes.
He served a jail sentence for the latter offence.
Detectives said there were signs of a violent assault at his home.