Moran, 51, was photographed looking worse for wear outside a Holiday Inn in Corydon, Indiana, at the end of last month, after reportedly being kicked out of the trailer she shared with her husband Steve Fleischmann.
The aging actress and three of her Happy Days co-stars, Don Most, Anson Williams and Marion Ross, plus the estate of Tom Bosley, who died in 2010, filed a million breach-of-contract lawsuit against CBS, which owns the show.
He was arrested at around midday by detectives from Operation Yewtree, the investigation set up in the wake of the Jimmy Savile child sex revelations.
It is understood the man, who was questioned locally, was also an entertainer, who had worked with Mr Davidson in the past.
They are the ninth and tenth people to be arrested as part of Operation Yewtree, which is investigating allegations of abuse involving Savile and others.
A spokesman for Scotland Yard said the arrests were not connected to allegations involving Savile.
The spokesman said: “Officers working on Operation Yewtree have today arrested two men on suspicion of sexual offences.
“A 53-year-old man was arrested at approximately 8am at an address in Hampshire and taken into custody locally.
“A 59-year-old man was arrested at approximately midday in west London and taken into custody at a London police station.” Other high profile names who have been arrested as part of the wide ranging investigation include the entertainer and comedian Freddie Starr, the former pop star Gary Glitter and the publicist Max Clifford.
But one founder member of the Rolling Stones has been largely relegated to the background, his part in the band’s musical history often overshadowed by his more personal history of serial womanising - and most notoriously his marriage to an 18-year-old when he was 49.
On Wednesday afternoon a uniformed police officer entered Mr Davidson’s detached home in Stockbridge, Hampshire as three other people, believed to be plain clothes detectives also went inside.
One of the men answered the door at the cream coloured property and said “we cannot comment” before closing it again.
Four men and a woman, believed to be police officers left the property carrying documents and a large red box at around 7pm turning all the lights off and locking up as they did so.
The arrest came several hours after a 53-year-old man from Hampshire was also arrested as part of the same investigation.