The alleged attack occurred at Frankland Prison in the British city of Durham this month. Barot, who was convicted of planning a terrorist attack on New York, has since been transferred to Royal Victoria Infirmary for medical treatment, The Mail on Sunday said.

The transfer of the 35-year-old was deemed necessary as he required specialized treatment for his scalding burns.

Concerns for the al-Qaida operative's safety previously had prompted officials to relocate him from a London facility to Frankland Prison.

Barot admitted in 2004 to planning several terrorist attacks, including bombings of the World Bank and the New York Stock Exchange. He was charged with planning chemical, toxic and bombing attacks and received a life sentence with a minimum term of 30 years in prison, the newspaper said.