Under fire from opposition parties over the law and order situation, the Uttar Pradesh government has ordered a CB-CID probe into the alleged rape and murder of a 14-year-old girl in Lakhimpur district.

An FIR has been lodged against a sub-inspector and two policemen for tampering with evidence. The government has also ordered a fresh post-mortem of the victim by a panel of doctors from other districts.

Missing since Friday evening, the girl was found hanging from a tree inside the premises of Nighasan police station. The victim's mother in her complaint had alleged that the girl was raped and murdered.

"At a high-level meeting late last night, it was decided that the probe into the death of the girl should be handed over to the CB-CID," a senior police officer said today.

The CB-CID has been asked to submit its report within a week's time, the officer said. The government has also rejected the preliminary post-mortem report which stated asphyxia as the result of death.

"It has been decided that a second post-mortem will be conducted by a panel of doctors from other district," he said.

The officer said that divisional commissioner Lucknow Prashant Dwiwedi and IG range Subesh Kumar have been asked to visit Nighasan and take stock of the situation. NHRC had yesterday decided to send a probe team to the spot.

"The Commission has decided to depute its investigation team for conducting an on the spot inquiry into the incident. It has also decided to issue notice to the director general police of the state, calling for a detailed report in the incident within four weeks," an NHRC spokesperson said in New Delhi.

Lakhimpur police had yesterday ruled out that the girl, who was found hanging inside the premises of a police station in Nighasan, was murdered citing the post-mortem report.

"The post-mortem report mentioned asphyxia, as a result of hanging, the cause of death which rules out the allegation of murder," superintendent of police D K Rai had said. He said there was no injury mark on the victim's body and there was a minor abrasion on her right leg.

"To confirm the second allegation of rape, a slide had been sent to a hospital for testing and a final conclusion will be drawn only after the report is received," the SP said.

Eleven policemen posted there were suspended after her body was found. Congress and BJP have staged demonstrations to protest against the incident.

Union minister of state for surface transport Jitin Prasad said the incident was an example of "deteriorating" law and order situation in the state.

Senior BJP leader Kalraj Mishra said: "This is a barbaric incident and suspension of policemen is nothing more than farce."

The Samajwadi Party said that a fact-finding committee of the SP led by leader of the opposition in Vidhan Parishad Ahmad Hasan would be visiting Nighasan on June 14.

"The committee, constituted on the directive of state president Akhilesh Yadav, will submit its report with party supremo Mulayam Singh Yadav," SP spokesman Rajendra Chaudhary said.