A billionaire Chinese hotel magnate is feared dead after a helicopter crash in southwestern France, where he was flying over a Bordeaux wine estate he had just purchased.

Rescue teams were scouring the Dordogne river on Saturday for the bodies of Lam Kok, who owned the Hong Kong-based hotel group Brilliant, his interpreter, and French wine entrepreneur James Gregoire.

The body of a fourth occupant, Lam's 12-year-old son, was pulled from the underwater crash site early on Saturday.

Gregoire had sold Lam the vineyard and was piloting the private helicopter when it went down on Friday.

Lam's wife had pulled out of the flight at the last minute, saying she was "scared of helicopters," according to a report from the AFP news agency.

Diplomats from China's embassy in France were at the scene "to follow the search and provide assistance to the families," local French officials said in a statement.

'It's unthinkable'

A lavish event on Friday marked 46-year-old Lam's purchase of the wine estate and chateau.

Afterwards, Gregoire offered to take Lam on a short helicopter tour of the grounds, and was seen patiently carrying out his pre-flight procedures.

"We can't believe this," the vineyard's managing director, Xavier Buffo, said after learning of the crash. "We can't take it in; it's unthinkable."

Police divers were searching the river for the bodies on Saturday, while officers with dogs scoured the river banks. Strong currents were complicating the search for the three missing, officials said.

Gregoire himself had bought the property, the largest in Bordeaux's Fronsac wine-producing region, in 2003 - a year after the previous owner died in a plane crash.

Source: Agencies