A confessed drug trafficker decided to give evidence against his alleged supplier because he felt that people should take responsibility for their actions, a court was told yesterday. Mak Kwok-lam, who pleaded guilty to trafficking heroin in August last year, was giving evidence against Ngai Wing-fai, who has pleaded not guilty to two counts of trafficking in dangerous drugs, when he told the seven-person jury that it was not the prospect of a reduced sentence that convinced him to testify. 'Everyone in prison knows that a sentence may be reduced [for helping prosecutors] ... but I am not giving evidence for this reason,' said Mak, who was arrested after Ngai allegedly handed him a plastic bag containing a biscuit box with 250.38 grams of heroin in it. '[I am testifying] because I know he did not plead guilty and I think one should bear responsibility for what one has done.' Ngai is charged with trafficking in the 250 grams that Mak was caught with, as well as a further 385.33 grams of heroin that was found in a Yau Ma Tei hostel room for which he was allegedly carrying a key. Mak, a casual restaurant worker, has also pleaded guilty to carrying seven small bags of heroin. He testified yesterday that he came to be a courier after running into a man, called 'Ah Man', he had known in prison. Ah Man had suggested Mak 'assist' him if he had nothing better to do and later introduced him to another person called 'Ah Hoy'. Ah Hoy would call Mak if there was any work - drug running - to be done. On February 26 last year Ah Hoy asked Mak to meet him at a store in Shamshuipo. It was at that store that Mak alleges he met Ngai, who was carrying a shopping bag. Mak said he headed to Mongkok where he was to drop off the bag. However, as soon as he arrived at his destination, he was arrested by customs officers. Simultaneously, Ngai was seen to get in a taxi and head towards Mongkok, where he was also arrested. Ah Hoy got away. The trial continues today before Mr Justice Peter Nguyen.