PR guru Max Clifford has been arrested by detectives investigating the Jimmy Savile sex abuse scandal and will "assist the police as best he can", his lawyer said.
The publicist was held at his Surrey home on suspicion of sexual offences and taken to a central London police station for questioning.
He was arrested as part of Operation Yewtree, the investigation into allegations of sex abuse surrounding Savile and others.
Charlotte Harris, of law firm Mishcon de Reya, said: "Max Clifford is being interviewed by police. Mr Clifford will assist the police as best he can with their inquiries. When we are in a position to provide further information, we will."
Scotland Yard is leading the national investigation into claims made against the disgraced TV presenter and other figures in the entertainment industry.
Clifford is the fifth suspect to be arrested - and the sixth person to be questioned - in connection with the Yewtree operation, which has already cost around £2 million and involves a team of 30 officers.
Last month he publicly questioned where the police inquiry might lead and said a lot of old stars were worried about being dragged into the investigation because they had appeared on Top Of The Pops or Jim'll Fix It and had merely posed for photographs with girls and Savile.
"It is a situation which could easily turn into a witch hunt, a lot of big stars are frightened," he told ITV's Daybreak. "Where is it going to end? I hope they (the police) concentrate on finding people like Jimmy Savile who were manipulating girls."
His arrest follows the questioning by detectives last week of a man in his 80s from Berkshire, as part of the investigation that does not directly relate to Savile.
Gary Glitter, comedian Freddie Starr, DJ Dave Lee Travis and a man in his 70s, reported to be former television producer Wilfred De'Ath, have been arrested and bailed as part of the investigation.