Mr Singh has 'not received a single visitor in prison'

Kashmir Singh was sentenced to death for spying in 1973 and is set to be reunited with his family.

Mr Singh was discovered by Ansar Burney, a social worker who tracks people lost in Pakistan's jail system.

Hundreds of servicemen and civilians were imprisoned by India and Pakistan during hostilities between the two sides in 1965 and 1971.

Spies

Mr Burney discovered Kashmir Singh on a recent trip to a jail in Lahore and persuaded President Musharraf to revoke his death sentence and order his release.

The elderly Indian was a former policeman who had become a trader in electronic goods.

"I feel better. I am happy," Mr Singh told reporters.

He was arrested in the city of Rawalpindi in 1973 and convicted of spying.

Pakistan and India frequently arrest each other's citizens, often accusing them of straying across the border - some are treated as spies.

Mr Burney is currently the government's caretaker minister for human rights.

He first heard of Mr Singh during a radio call-in show some years ago. He recently won a presidential pardon for the prisoner.

The BBC's Barbara Plett says that Mr Singh is expected to be reunited with his wife and three children on Tuesday morning.

Mr Singh told Mr Burney that he had a love marriage rather than an arranged marriage.

His wife confirmed this to the minister when he called her.

"Why else would I have waited 35 years for him?" she asked.

Local media reports say that she has been waiting at the border since she first heard news that her husband would be pardoned.

Mr Burney said last week that Mr Singh was held in a condemned prisoners cell for most of the time since his conviction and had become mentally ill.

He said that he was first informed about Kashmir Singh several years ago by members of the Indian community in London.

But he was unable to locate Mr Singh, despite visiting over 20 prisons across the country in relation to his campaign for prison reforms and prisoners' rights.

The minister said that Mr Singh had not received a single visitor or seen the open sky and like other condemned prisoners, was locked in an overcrowded death cell for more than 23 hours a day in conditions which the minister described as "hell on earth."

Mr Burney said he will travel to India on Tuesday to see Mr Singh re-unite with his wife as well as their two sons and a daughter.

"My real purpose in going with him to India is that when this pair of swans meet after 35 years, I want to capture it with my own eyes," he said.