Lucknow, Aug 14 - A 38-year-old prisoner lodged in Uttar Pradesh's Jalaun district jail was set on fire early Friday, allegedly by some other inmates after he refused to give extortion money.

While jail authorities were not willing to come on record, a senior police officer said: 'What led to the incident can be only confirmed after an inquiry.'

Additional Superintendent of Police Rajesh Kumar told IANS on phone: 'Shobran Singh suffered burns on 90 percent of his body. He is undergoing treatment at the district hospital, where his condition is critical.'

'We have recovered a can containing kerosene oil from the site. Even as the reason behind the incident is yet to be ascertained, the recovery of the can from the site definitely reflects the negligent attitude of the jail officials,' he added.

The district administration has ordered a magisterial probe into the matter.

'Stern action would be taken against those found involved. The case is a serious one and needs to be probed comprehensively,' said sub-divisional magistrate Arun Dwivedi.

Jalaun is about 200 km from Lucknow.