For the first ever in Thailand and perhaps the world, women inmates will be allowed into a men's prison where both sexes will work together on vocational activities for limited periods under close supervision, officials said last Friday.

Although no physical contact will be allowed, officials hope the move will discourage growing homosexual behaviour in prisons, said the Thai Corrections Department.

Thai officials have gathered anecdotal evidence that "homosexuality" is growing among the 250,000 inmates, including 50,000 women, in the country's 132 prisons.

The experiment will see 922 female inmates in a prison in the northern Nakhon Sawan province will work with the men during vocational training and will be escorted back to their women's zones after their activity.

The programme will be expanded to other prisons nationwide if the initial experiment is successful although there are no plans to house men and women together in prisons, said Nathee Chitsawang, deputy director general of the Corrections Department.

"Male prisoners don't dare to look in the eyes of females when they come across each other," Nathee said. "This behaviour has created the problem of homosexuality and we hope that mixing the sexes would help lessen the problem," he added.

Thai officials say that same-sex relations are causing more tension in the country's notoriously overcrowded prisons, designed to hold just 100,000 - less than half the number of total prisoners.