Notorious gangster Yip Kai-foon believes a witness could clear him over the 1996 shootout with police that ended his criminal career - and is offering $500,000 to anyone who knows where she is.
But he will only pay up if identifying her results in him being cleared.
Yip was arrested on the waterfront in Western early on May 13, 1996, and later convicted of shooting at police and possessing explosives over the incident, in which gunshots left him paralysed. He is serving a 36-year sentence in Stanley Prison.
The reward is being offered through his lawyers, Andrew Lam and Co.
Mr Lam said last night that a woman passer-by in her 40s had witnessed events leading up to his client's arrest.
Yip did not know the identity of the witness, Mr Lam said, and his client's instruction was to find her in order to 'revoke the verdict'.
The law firm intends to place an advert on behalf of his client stating that Yip would pay a $500,000 reward to anyone who could give information about the whereabouts of the woman that resulted in the overturning of the guilty verdicts on the shootout charges.