New Delhi, Sept. 24 -- The Supreme Court on Wednesday asked the Centre why death-row prisoner Balwant Singh Rajoana has not been hanged, who was held guilty for the assassination of the then Punjab Chief Minister Beant Singh in 1995, till now.

A bench of Justices Vikram Nath, Sandeep Mehta and NV Anjaria remarked after the Centre said it was a "serious offence".

The bench asked Solicitor General KM Nataraj, representing the Centre, "Why did you not hang him till now? Who is to blame for that? At least, we have not stayed the execution."

The apex court was hearing the plea of Rajoana seeking commutation on the grounds of delay in considering the mercy petition pending before the President of India since 2012.

Senior advocate Mukul Roha...