Motive behind Thailand hotel poisonings

Six people died at a luxury hotel in Bangkok after drinking tea laced with cyanide with one of the dead believed to be the killer.

An American-Vietnamese woman is believed to have poisoned five of her relatives in a luxury hotel in Thailand over huge debts, police say.

Sherine Chong, 56, is thought to have laced tea with cyanide before feeding it to the group of three women and two men.

Police believe that Chong drank the substance last.

Four of the bodies were found in the living room and two in the bedroom.

Two appeared to have reached for the door but collapsed before they could make it, police said.

American Vietnamese woman Sherine Chong is believed to have killed five people with cyanide-laced tea before poisoning herself at an upscale Bangkok hotel after a legal dispute over bad investments. Picture: Supplied

A CCTV clip allegedly showing Sherine Chong, who is believed to have poisoned her family, at the hotel. Credit: EPA

The three dead women were named as 46-year-old Nguyen Thi Phuong, Sherine Chong, 56, and Nguyen Thi Phuong Lan, also 46.

The male victims are Tran Dinh Phu, 37, Dang Hung Van, 55, and 49-year-old Hong Thanh Pham.

According to Khaoso, Ms Chong’s motive for murder stemmed from her huge debts.

She had persuaded a couple in the group to invest in a hospital in Japan but they ended up losing around 10 million baht (AUD$535,826).

They had been chasing her for the money but she declined to pay them back.

One of the women makes her way through the courtyard.

Another male victim jogs towards the entrance.

The group decided to meet at the impressive Grand Hyatt Erawan Hotel, in Bangkok, to resolve the problem but Ms Chong is thought to have poisoned the group and herself in a shocking a murder-suicide.

The bodies were discovered by a maid after the room had been locked from the inside.

CCTV footage from the hotel shows some of the five victims arriving at the hotel, towing their suitcases as they made their way to the room.

Another CCTV image shared in local media purports to show Ms Chong in the hotel before the murders.

Cups and thermos flasks found with traces of cyanide inside. Credit: EPA

Mostly untouched room service food found at the crime scene. Credit: EPA

Pictures of the murder scene showed a table covered in teacups and thermos bottles, in which police later found traces of cyanide.

Nearby lay a selection of untouched food that was delivered on Monday afternoon before the tourists were found dead.

There were no other visitors and no one was seen leaving.

Post-mortem results confirmed cyanide was present in the cups and bodies of the victims.

Ms Chong waited in a hotel room on the fifth floor for her alleged victims and ordered tea and food from room service before they arrived, police said.

She refused an offer from staff to make the tea for her, the Bangkok Post reports.

A seventh person outside of the group of victims is believed to have booked the hotel room but they are not a suspect.

Police say she is the sister of one of the victims.

The victims included four Vietnamese nationals and two Vietnamese- Americans.

Ms Chong had both a Vietnamese and US passport and had visited Thailand five times before.

Thai Prime Minister Srettha Thavisin said the FBI are heading over to investigate.

Police said a mass suicide was unlikely because some of them had arranged future parts of their trip, such as guides or drivers.

US State Department spokesperson Matthew Miller offered condolences to the families of the dead.