Sources said the Tihar administration received a Supreme Court order along with an application demanding the custody certificate of an inmate, Babbu Singh, lodged in the jail.

However, when Tihar officials saw the order they decided to verify it with the Supreme Court. “There were many loopholes in the order. We immediately contacted the apex court registrar, who after verification told us the order was indeed forged and also directed us to take legal action against the applicant,” a senior Tihar official said.

The Tihar administration lodged a complaint in connection with the matter at the Hari Nagar police station, on the basis of which an FIR was registered on Friday.

Police sources said the complaint they have received from the jail authorities mentions that one Ramakant had applied for the custody certificate of Babbu Singh. He is believed to be Babbu’s brother, the police said.

Deputy Commissioner of Police (West District) Sharad Aggarwal said: “We have registered a case and are probing the matter.” He said legal action is being taken against the applicant.

“Though he has not been traced yet, we are probing the matter and search teams have been constituted,” Aggarwal said.

Sunil Kumar Gupta, Tihar law officer, is the complainant in the matter, police sources said.

Sources said Babbu Singh is undergoing trial in connection with a murder case under Section 302 and is lodged in jail no. 4 in Tihar. He was arrested from the Naraina area of West Delhi.