WHEN two friends and Phuket workmates fell out over a debt, one dared the other to shoot him - so he did. The man died, and his friend and workmate now faces a murder charge.

One strange aspect of the case is the murder weapon, produced for media to inspect at Phuket City police station today. It is what's known as a pen gun, perhaps more correctly described as a short pipe gun.

Pijib Hawan, 34, who today admitted shooting dead Thongpon Eurapan, 30, last night around 9.10pm at a Phuket construction site camp, told police that he made the pen gun when he was at technical school.

It's a three-part weapon that could easily be hidden and at first glance does not look deadly. But when assembled, the short length of pipe, with its spring-loaded hammer, fires a .38 with the capacity to kill.

According to Phuket City police, construction site foreman Khun Pijib had asked his deputy, Khun Thongpon, to repay a 4000 baht debt. Khun Pijib ran a small shop on the Phanason Borei construction site in Vichit, selling essential supplies. But he thought it was time, just after pay day, for Khun Thongpon to settle the account.

Khun Thongpon was apparently reluctant to pay up. To show he meant business, Khun Pijib produced his technical college pen gun. Then he loaded it, and fired a shot in the air.

''Pay the money back,'' he told Khun Thongpon.

But Khun Thongpon was reluctant to settle his debt. ''You're joking,'' he is said to have told Khun Pijib. ''If you were serious, you'd shoot me.''

With that, Khun Pijib reloaded, and shot his friend and workmate. Khun Thongpon died in an ambulance on the way to Vachira Hospital in Phuket City.

Both men had come to Phuket from other provinces to find jobs. Khun Pijib now faces a long term in Phuket Prison, where the inmates are taught furniture-making, not metalwork.