HONG KONG (AFP) - A court battle over the fortune of eccentric Hong Kong tycoon Nina Wang began Monday, pitting a charitable foundation against a feng shui master for her estimated 13-billion-US-dollar ($18.95 billion) estate.

The eight-week trial will decide whether Wang, who at one stage was Asia's richest woman, left her entire fortune to businessman and feng shui master Tony Chan when she died of cancer in 2007 at age 69.

Opposing Chan's claim is Wang's Chinachem Charitable Foundation, which is now controlled by her siblings, who say a will awarding Chan the huge fortune is a fake.

Queues formed for seats in the courtroom's public gallery on the first day of the trial, while a scrum of photographers and cameramen tried to grab a shot of the star lawyers and a shaven-headed Chan as they entered the High Court.

Opening the trial, Chinachem lawyer Denis Chang said the court should ignore Chan's claim and instead recognise an earlier will, which awarded the estate to the foundation that Wang had set up with her husband Teddy.

"This is a court of law, not a court of feng shui," Chang told the court.

He said the 2002 will reflected Wang's true wishes before she became too ill.

"(Teddy and Nina) were childless. For them, Chinachem was their baby," he said.

Wang left an estate estimated to be worth up to 100 billion Hong Kong dollars ($18.85 billion), although the exact sum remains difficult to assess.

Before her death, the pigtailed, mini-skirt-wearing mogul fought a bitter eight-year court battle against her father-in-law for the estate of her late husband Teddy, who was kidnapped for the second time in 1990.

His body was never found and he was legally declared dead nine years after his disappearance.

During the fight for control of his estate, Wang was accused of forging her husband's will. She eventually won.

After his disappearance, Wang had built Teddy's company, Chinachem, into a real estate empire with more than 200 office towers and 400 companies around the world.

Wang never believed that Teddy had been killed and kept looking for him until her death, the court heard.

However, since her death Chan has claimed to have had a longstanding relationship with the billionaire and eventually became her lover.

Wang's family denies this and lays claim to the 2002 will. Chang said they will produce testimony from handwriting experts that prove Wang's signature on the later will is a fake.

Wang was nicknamed "Little Sweetie" because of her resemblance to her favourite Japanese cartoon character.

She was famously frugal, with reports saying she survived on fewer than 3,000 Hong Kong dollars a month by buying cut-price tickets, wearing clothes made by friends and eating at fast food joints, in particular Kentucky Fried Chicken and McDonald's.

In her last few years, she became increasingly fascinated with feng shui, an ancient Chinese system that claims to harness natural energies and is widely used by Hong Kong residents.

Feng shui masters such as Chan can command huge sums for their advice and have an almost cult-like following.