Sarabjit Singh, who has been on death row in Pakistan for the past 17 years, on charges of plotting bomb blasts in Lahore and Multan 'had unknowingly strayed into Pakistan', claims his fellow inmate.

"He (Sarabjit) is a simpleton, who had unknowingly strayed into Pakistan. I have even stayed with him in the same jail," said Mehboob Elahi, former Indian prisoner in Pakistan who was released from the prison in 1996.

"I have stayed with him in the same cell at Gujranwala jail. Not for a day or two, but at least a year and a half," 52-year-old Elahi told television channel NDTV.

There was another person with him called Malkiat Singh from Taran Taran in Punjab, he added.

Elahi was in his early twenties when he strayed into Pakistan and was arrested in Lahore on June 23, 1977.

He was convicted on espionage charges and sentenced to 14 years of rigorous imprisonment in 1980 and was released on December 1, 1996.