Sarabjit Singh, the Indian imprisoned in Pakistan for the last 22 years, has written to his sister Dalbir Kaur and Congress chief Sonia Gandhi, alleging mental torture at Lahore's Kot Lakhpat jail and a conspiracy to drive him mad or kill him.
The letter to Dalbir said Singh's health was worsening and the treatment being given in jail was useless.
To Gandhi, Singh urged that the government help arrange a Pakistani visa for his family to visit him.
"Something is being given in my food for the past 2-3 months that is gradually making my body useless," he wrote.
Singh's lawyer Awais Sheikh brought the letters to India.
Dalbir urged the government to send a team to Lahore jail. She also appealed to Pakistan President Asif Ali Zardari for her brother's safety.