By Jonathan Head
BBC News, Bangkok
The Santika nightclub was one of the most popular in Bangkok
An initial investigation into a fire at a Bangkok nightclub that killed 66 people has found serious failings by the police and city authorities.
The fire ripped through the club on New Year's Eve, and many people died because the building had only one exit.
Thai investigators said that the signatures of building inspectors had been forged repeatedly.
They also said the police ended raids on the club in 2005, after an unnamed person was made a shareholder.
While the police initially focused their attention on what caused the fire at the Santika Club, a parallel investigation ordered by the government has looked at a much bigger and more sensitive question - how was it that a building with no fire exits and no official permit to operate as an entertainment venue could stay open for four years?
This was not an obscure back-street club - the Santika was one of the most popular in Bangkok.
That second investigation has now released some preliminary findings; they report that the signatures of the building inspectors had been repeatedly forged, and that the club had avoided paying tax.
Party-goers emerged bruised and burned from the fire on New Year's Eve
More revealingly, they say police raids on the club - a common occurrence in Bangkok - mysteriously stopped in 2005, right after an unnamed person was made a shareholder.
Sources close to the investigation have told the BBC that person is a police colonel, and that many more police officers are implicated.
None of this will come as any surprise to those familiar with Bangkok's lively and lucrative nightlife.
Pay-offs to the police are a routine part of business, say nightclub owners - fire safety inspections are not.
But Thai Prime Minister Abhisit Vejjajiva has signalled that he wants this to change by ordering the Department of Special Investigations - Thailand's FBI - to take over the inquest into the Santika fire.
That increases the chances that any police role in this tragedy will be exposed.