BORDEAUX - French police stepped up their search Sunday for a Chinese billionaire and two others feared dead after their helicopter crashed as he was surveying a newly purchased vineyard in southwest France.
There was little hope of finding alive Lam Kok, a 46-year-old Chinese tea-and-property tycoon, his interpreter and advisor Peng Wang or winemaker James Gregoire after police on Saturday recovered the body of Lam's 12-year-old son from the back of the wrecked helicopter lying in seven metres (23 feet) of water in the Dordogne river.
The four had boarded the helicopter piloted by Gregoire on Friday to make a celebratory tour of a Bordeaux chateau and wine-growing estate that Lam had just bought from the Frenchman.
After pausing the search on Saturday night, divers resumed scouring the cold waters of the Dordogne around 9:00 am (0800 GMT) on Sunday, working in near total obscurity.
"We are meticulously combing the area, with practically no visibility, almost by hand," local gendarmerie commander Ghislain Rety said.
Police said strong currents were hampering the search.
Helicopters with infrared cameras were flying over the river and a special sonar designed for finding bodies had arrived from the French city of Strasbourg, Rety said.
Slowly dragged behind a boat, the sonar was to criss-cross the river between its banks.
Some 100 police were searching along the riverbanks and reinforcements were expected.
An autopsy was to be conducted Sunday on the body of Lam's son, Shun Yu Kok, but officials said there was little hope the reasons for the crash would be quickly identified.
"The causes of the accident have not been determined at this stage and most likely will not be for several weeks," local prosecutor Christopher Auger said.
The doomed flight took place after a lavish event Friday marking Lam's multi-million-euro purchase of the 65-hectare (160-acre) wine estate, Chateau de la Riviere.