New Delhi, Oct 30: Businessman Abhishek Verma, who is a witness in a 1984 anti-Sikh riots case against Congress leader Jagdish Tytler, on Sunday filed a police complaint claiming that he was threatened and demanded his polygraph test be carried on before a retired judge. In his complaint submitted to Mehrauli police station, Verma said that he received a threatening email on Saturday night on his company's general email address. "We have registered a case of criminal intimidation and the investigation is on," said Deputy Commissioner of Police Ishwar Singh. "In the said email, the language used in the email is extremely 'abusive and threatening', and threats have been extended to me and my family," Verma said in his complaint. Verma's advocate Maninder Singh told IANS that on Friday, Verma had moved a city court, accusing two forensic lab officers of defending Tytler during his lie-detector test and trying to force him to reach a compromise. "We have requested the court to appoint a retired judge or a judicial officer under whom the lie-detector test would be conducted in a fair way as we do not have faith in forensic lab officers anymore," he said. On the threat, Singh said that the unknown mailer has threatened to kill Verma and his family. "He has threatened him to drop the idea of 'deshbhakti (patriotism) and not to continue with his polygragh test at Forensic Science Labortory as a witness against Tytler," he added. The local court had on the last date put up the matter for hearing on October 30 when the Central Bureau of Investigation will also provide a status report on the test. Tytler is accused of leading a mob in Pul Bangash area in 1984 that led to the killing of three Sikhs and Verma accused him of influencing witness Surender Singh through money and a promise to send his son Narender Singh to Canada. The CBI had earlier given a clean chit to Tytler in the case but reopened investigation following a December 4, 2015 court order in the wake of the allegation.