TWO men accused of holding a garage owner for about 10 hours after he failed to repay a $1.16 million gambling debt were acquitted of the charge in the District Court yesterday. However, Ng Tai-sum, 32, was found guilty of two counts of common assault and sentenced by Judge Burrell to three months' imprisonment, suspended for two years and fined $20,000. Ng had been accused of assaulting Wu Siu-sang, then 31, at a Tsim Sha Tsui restaurant and a Yau Ma Tei sauna on December 19, 1991. He had also been jointly charged with Man Tung-sing, 29, of false imprisonment, but both were found not guilty of this charge. They had denied all charges. It was the Crown's case that both defendants and three other men had unlawfully detained Mr Wu from early morning until the afternoon at different locations. Prosecuting counsel Chu Tak alleged that cash and property, valued at about $100,000, were handed to the men. Judge Burrell, in acquitting Ng and Man of false imprisonment, said he accepted the testimony of two officers who questioned Mr Wu outside the Tai Hing goldsmith shop in Tuen Mun at 11 am. While Mr Wu claimed he had complained about the alleged assaults,the officers said he had only told them they were sorting out a gambling debt. Judge Burrell said this raised doubts. about whether Mr Wu had exaggerated the allegation of false imprisonment.