Hong Kong's highest profile probate battle began yesterday, pitting the family of Nina Wang, once Asia's richest woman, against a reclusive businessman, with the prize her vast fortune.

The hearing, scheduled to run for eight weeks, centres on the validity of conflicting wills. In a trial that is set to captivate Hong Kong, handwriting experts and feng shui gurus will also testify.

Ms Wang, who died of cancer in 2007, was known as "Little Sweetie", thanks to her trademark pig-tails, heavy make-up and mini-skirts.

The Chinachem charitable foundation, controlled by Ms Wang's family, has claimed that a 2002 will made it the beneficiary of her estate, which has an estimated value of at least $3.9bn (€2.9bn, £2.6bn). The foundation claimed Ms Wang had wanted to leave her fortune to a charity and establish a Chinese Nobel prize.

But Tony Chan, a married feng shui master who claims to be Ms Wang's secret lover, says she wrote a new will in 2006 in which she named him as the sole heir. Mr Chan, who emerged from anonymity only after Ms Wang's death, attended the hearing yesterday.

The case echoes the epic inheritance battle between Ms Wang and Wang Din-shin, her estranged father-in-law, over the multi-billion dollar estate of Teddy Wang, Ms Wang's husband, who was declared dead in 1999, nine years after he disappeared during a kidnapping.

Ms Wang in 2005 won that lawsuit and, with it, control of Chinachem, a private property developer, making her Asia's richest woman.

In yesterday's hearing Denis Chang, barrister for the foundation, said the 2006 will had been forged as Ms Wang had never regarded Mr Chan as her heir. Mr Chang said she was too ill in 2006 to sign a new will.

He said Mr Chan was Ms Wang's feng shui master and had received millions of dollars for his advice. The case continues.

Additional reporting by Tracy Tu