TWO illegal immigrants tied a taxi driver to a tree, took his vehicle to use as a getaway car in a planned holdup, and later held a hostage in a cold storage room, the High Court heard yesterday. Lam Chi-piu, 25, and Yeung Chi-wai, 24, both pleaded guilty to one count each of robbery, possession of a firearm at the time of the crime, conspiracy to rob and false imprisonment. Yeung also admitted a second false imprisonment charge. They will be sentenced by Deputy Judge Daniell on February 12. Senior Crown Counsel Mr Sean Kelly told the court Lam, Yeung and a third man held up taxi driver Mr Fung Wing-on at gunpoint on January 17 last year in Tseung Kwan O. They robbed him of $500 and escaped in the taxi after tying him to a tree. Mr Fung managed to free himself and reported the matter to police. The vehicle was later found in Kai Tung Road. The gang allegedly ran into the Swire Air Catering Services premises in the Cathay Pacific Airways building. Police surrounded the building. Lam was caught soon after. Yeung was arrested after taking a hostage. Under caution, both Lam and Yeung admitted the taxi robbery and confessed that the vehicle was to be used as a getaway car in a holdup they had planned to commit that evening.