A French architect with ties to the family of the disgraced Chinese politician Bo Xilai is under arrest in Cambodia and could be extradited to China, police have said.

Patrick Devillers knew the ousted leader and had business links with his wife, Gu Kailai - now detained on suspicion of murdering another member of her circle, the British businessman Neil Heywood.

"There was an arrest of this French man in relation to a crime in China," Touch Narouth, the Cambodian capital's police chief, told Reuters.