Two police officers were convicted yesterday of plotting to forge the signature of a suspected double murderer who died during questioning. In the District Court, Judge Gareth Lugar-Mawson said Detective Sergeant Chong Kwok-wah, 45, and Detective Constable Wong Sek-wah, 33, had conspired to pervert the course of justice. The judge said the conduct of the pair, who denied the charges, might have misled the Coroner's Court over Lam Tin-ming's death on November 22. He accepted the evidence of two forensic scientists that Lam's signature in a statement recorded on the day of his death and in a police notebook were forged. The judge said the two policemen were lying when they told investigating police they had seen Lam sign the documents. In the statement, Lam, 56, admitted he had killed a man. Police also suspected him of murdering another man. The pathologist's report said Lam died of a heart attack after three hours' questioning at the New Territories regional crime headquarters. But the judge said it was impossible to speculate whether the forgeries were placed on the records before or after Lam's death. Kevin Egan, defending Chong, and James Chandler, for Wong, urged the judge to pass suspended sentences. Mr Egan said the defendants had panicked and were trying 'to tie the matter up'. Judge Lugar-Mawson adjourned sentencing until September 23. He extended the defendants' bail but ordered them to surrender their travel documents.