By Simon Ingram in Bangkok

For most residents of Bangkok, night-time on the streets is a time of danger.

However, for people like Sanae Butrnark of the Por Teck Teung Foundation Rescue Unit, the night creates opportunities.

He is at the wheel of his specially-equipped pick-up truck and he is on the lookout for trouble.

This does not take long. A radio message says that there has been a fatal traffic accident on the city outskirts. This is enough to send Sanae on a high-speed dash to the scene.

Fighting over bodies

By the time he arrives, other staff of the charitable foundation he works for are already there.

"This is what happens at many accidents,'' Sanae says.

"We can get a volunteer there within five to ten minutes, even before the police arrive."

Thailand's all-too lethal highways are rich hunting-grounds for the rival rescue organisations who make violent death their business.

Competing teams of rescuers have come to blows trying to recover the same body before it reaches the morgue.

The foundation keeps unclaimed accident, murder and suicide victims in special graveyards.

Out with the old, in with the new

Periodically the corpses have to be dug up to make way for new arrivals - a task the volunteers who do the job believe will earn them spiritual merit points.

"We don't call it digging up corpses,'' says volunteer Somjit Petkal. "This is digging for gold."

The skulls and other bones are scrubbed clean before they are stored.

This may seem like gruesome work but for some ethnic Chinese women it is a charitable deed that is good for the soul.

"We Chinese believe that by helping dead people we earn a lot of merit," says a member of the Por Teck Teung Foundation.

"That's why the foundation helps dead people who don't have family."

Profits

The foundation takes in thousands of dead in the course of a year.

However, there is more than piety involved here. There are the substantial sums of money that the rescue organisations solicit in donations from devotees.

It is an open question whether they should be profiting from a public service that the government ought to be providing.

"We don't have enough manpower or maybe enough money to do it, so the charity organisations perform this kind of function,'' says sociologist Dr Nithet Tinnakul.

''But of course there's money involved in that too," he adds.

Gold leaf

Ninety years after it arrived in Thailand, the Por Teck Teung foundation's extraordinary traditions are flourishing.

Once they have been exhumed, the skulls and other remains are decorated with gold leaf and sprinkled with rose water ready for the journey that lies ahead.

They will eventually be cremated to make way for others and the cycle will begin all over again.