Government Railway Police have launched a search for a person masquerading as a senior police officer posted with the special task force (STF), who has duped several officials.

Several police station house officers (SHO) have fallen into the man's trap. The police have identified the alleged imposter as Lal Mohan Rai, a resident of Katharia from East Champaran district's Lakhaura police station area. An investigating officer said Rai has been on the run since the police came to know about his activities.

He would allegedly call the station house officers on their official cellphones, identify himself as a deputy superintendent of police or a STF superintendent of police and ask them to immediately hand over money to a person he claimed was on the police's radar.

Sources in the police said the conman would collect money from lower-rank officers posing as a reader (clerk) in the office of the deputy inspector-general or the inspector general (IG) of railway police. His recent victims were the Government Railway Police station house officers at Bapudham Motihari, Muzaffarpur and Bettiah.

Lal would allegedly thank the officers for the money and leave.

"He asked me to immediately reach Lakhaura (in East Champaran) and hand over Rs 5,000 to one Ashok Yadav, the driver of an earthmover machine," said an SHO posted in north Bihar. "I obeyed him as he had introduced himself as the deputy superintendent of police of the STF."

"He told me Ashok was involved in the abduction of a girl from Patna and the money had to be handed over to him so that the police could trace him."

The SHO said he realised his folly when "the officer" didn't turn up after a week.

Muzaffarpur superintendent of rail police B.N. Jha said an FIR has been lodged with Bapudham Motihari GRP against Lal. "The station house officer of Bapudham GRP, Arvind Kumar Mishra, has been asked to arrest the fraud," Jha said.

East Champaran superintendent of police Jitender Rana said raids are on to arrest Lal.