The main witness in the 1984 anti-Sikh riots case Abhishek Verma has filed a complaint about facing threats.The complaint was filed in the Maidangarhi police station in South Delhi which says that he received a threat on email to withdraw as a witness.Verma said the threat was explicit that he and his family would be blown up by a bomb if he did not do as directed in the threat.Verma is the chief witness in the CBI versus Jagdish Tytler case. The mail sent to Verma says that howsoever strict security may be provided to him but Verma will not be allowed to reach the court premises to depose in the matter.If he does not withdraw as a witness, then his car and house will be blown up by RDX explosives, the mail said. Verma has earlier also received threats and the court was informed.The police is said to started acting on the complaint received from Verma. He has also pinpointed some Congress workers said to be part of this threat message and the police is investigating.The Delhi High Court in September last year directed the police to continue providing three security personnel round the clock to controversial arms dealer Abhishek Verma, a witness in a 1984 anti-Sikh riots, as he was receiving threats.