A SECURITY guard was yesterday accused of trying to implicate colleagues to deflect suspicion during police inquiries into Hong Kong's biggest robbery. Yiu Chung-keung, 31, commander of a Guardforce van robbed of $167 million, had told police one security guard had been sacked the week before the raid and another had financial problems, the High Court heard. Mr Yiu, giving evidence for the prosecution against alleged robber Cheung Tze-keung, 38, admitted giving police details of other guards. Businessman Cheung has pleaded not guilty to being one of three men who carried out the robbery. Daniel Marash, defending, asked him: 'Were you not trying to deflect suspicion away from yourself and onto others?' Mr Yiu replied: 'No. I was assisting the police and carrying out the duty of a citizen.' He denied that he felt police were treating him as a suspect. Mr Yiu was interviewed by the police six times after the robbery outside Kai Tak airport on July 12, 1991. He had been asked about discrepancies between his statement and those of other people, the court heard. The police had also questioned him about alleged breaches of security at the time of the raid. They asked why the escorting van was not at the scene, why Mr Yiu did not use his radio to try to contact the van, why his vehicle stopped outside the airport to drop off a member of staff and why one staff member did not turn up for work on time. 'Did you never feel you were under suspicion yourself?' asked Mr Marash. 'No, I did not feel it at all. I explained everything to the police in my statement,' Mr Yiu said. He said he had told police about a security guard sacked the week before the robbery. The guard had told colleagues as long as he was around they should not panic, even if there was a robbery, the court heard. The guard was said to have been interested in Mr Yiu's background and details of how much money was being carried and to which bank it belonged. 'He was not responsible at work. He would not lock the safe and he was lazy,' Mr Yiu said. Another guard had money problems and often tried to borrow cash from colleagues, the court heard. The trial before Mr Justice Duffy continues today.