Sukanta Sarkar alias Ravan (37) was in the lock-up of the SDJM's court in Asansol before being produced when he set himself on fire and sustained 80 per cent burn injuries, police said.
He was taken to the Asansol Sub-divisional Hospital.
However, it was yet to be ascertained how he was able to set himself ablaze in the court lock-up in presence of policemen.
Sarkar was arrested on August 10 last year on charge of raping and murdering a seven-year-old girl.