All five members of the family were found dead in their beds yesterday morning without any trace of a struggle.

The tragedy took place as breadwinner Boonchai Surawuthipong, 49, was clearly worried that his debtor would harm his children.

In one of the notes he left, Boonchai said a man called "Choosaeng" had ordered a mafia gang to abduct his children in a bid to demand repayments.

Boonchai also left a suicide note: "Dad and mom, I am so sorry for causing you problems all along. I have made several wrong decisions. I am so sorry that I haven't repaid you for what you have done for me. Now, I've decided to take my family with me because of debts."

According to police, Boonchai borrowed Bt800 million from a bank to expand his factory many years ago. Later, he needed a further Bt130 million and Choosaeng offered to help him secure the loan for a service charge of at least Bt4million.

Boonchai obtained the loan but had yet to pay Choosaeng any of the money.

"We are going to do a background check on Choosaeng," said Police Colonel Charn Saengsiangfa, a superintendent at the Metropo-litan Police Division.

At the time of Boonchai's death, his luxury mansion had just been completed and still needed some more interior decorating. Many luxury cars were parked inside the compound.

All three children of Boonchai and his wife Penphimon, 40, had studied at Bangkok Patana School.

They were five-year-old Panich, 15-year-old Nattamon, and 18-year-old Nattanich.

The bodies of Boonchai, Penphimon and Panich were found in the same bed. Nattamon and Nattanich died in their own beds in two different bedrooms.

Servant Poon Chanhom, 50, said he and a housemaid immediately alerted police after finding the whole family dead.

Poon had worked for Boonchai for a long time, first as a driver then as a handyman when his sight deteriorated.

"My employer was a good, kind-hearted man," Poon said.

According to Poon, Boonchai used to operate a small perfume-oil factory. Buoyed by bright business prospects two years ago, Boonchai decided to buy a 20-rai plot of land and built a large factory and a luxury house.

The house was only just completed and Boonchai took his wife and children to live there two weeks ago.

Bangkok Patana School manager Pornpimon Charoen said she knew all three of Boonchai's children.

"But we never knew about their family's financial problems," she said, adding the family was never late in paying tuition fees.