The court asked the director of public prosecutions to follow up the case. Yuen died in 2008 without leaving a will.

The nine false documents - including minutes of meetings and share certificates - were dated over 101/2 years and signed by Lo.

But the appeal judges accepted evidence that the 'fingerprint' of the ink - the impurities in the dye that make each manufacturer's batch unique - showed that Lo's signatures were all made with the same ink, in the same pen and after Yuen's death.

The judges also ruled it was 'inherently improbable' that Yuen would have transferred his assets to Lo in 2001, a year after they stopped living together. Lo's appeal was dismissed by Madam Justice Maria Yuen Ka-ning, Madam Justice Susan Kwan Shuk-hing and Mr Justice Mohan Bharwaney.

They ruled that the shareholdings in Asian Powers belonged in Yuen's estate, which is administrated by his son Francois Yuen Ming-hwa. Asian Powers comprises four property-holding companies that make up the majority of Yuen's estate.

Forensics expert Valery Aginsky said that after examining the 'fingerprint' and the age of the ink dye, he concluded the ink in the nine signatures came from the same manufactured batch. He also said the signatures were written with the same pen.

Bharwaney wrote: 'Although it was theoretically possible that two batches [of ink] could be indistinguishable, this could only happen if exactly the same components, with exactly the same impurities, were used. However, in practice, this could not occur as the impurities were impossible to control.'

He ruled that the lower court was right to conclude last September that Lo had a propensity to 'engage in deceptive and fraudulent conduct' to reward herself from Yuen's estate to the disadvantage of his children.