By Chris Hogg BBC News, Hong Kong

Nina Kung has built up her late husband's firm Chinachem

Prosecutors dropped charges that Nina Kung falsified the will and attempted to pervert the course of justice.

Her father-in-law had claimed that he was in fact his son's legal heir and had documents to prove it.

Each twist and turn of the high-profile court case dominated Hong Kong's front pages and gossip columns.

The territory's tycoons, their lavish lifestyles and often bitter family feuds, are a source of fascination for many people here.

This saga began with the kidnapping of businessman Teddy Wang 15 years ago. He was never seen again and nine years later he was declared dead.

His estate was valued at around $5bn.

'Glad it's over'

His widow and his father each presented a different version of Teddy Wang's will.

The one Nina Kung had, which was handwritten, left his fortune to her.

Ms Kung, seen here in 2002, is known for her exuberant dress sense

But the elder Mr Wang insisted his was the authentic one and proved that he was the rightful heir.

He began a civil case against his daughter-in-law, accusing her of forgery.

At first, two lower courts ruled in his favour. That prompted the police to launch a criminal investigation.

Then, three months ago, another court hearing the civil case, overturned the earlier rulings and declared Miss Kung's will was authentic.

That led to this decision to drop all criminal charges against her.

It has taken years to clear her name but Miss Kung, who has reverted to her own family name, showed little emotion in court.

Afterwards, in a statement, the multi-billionaire said simply she was glad it had come to an end.