A physician at the Police General Hospital who conducted a test on two samples of seized "powdered milk ketamine", found near dead victims on Tuesday, revealed that the tests detected the presence of four substances -- ketamine, heroin, ecstasy and a sleeping pill called diazepam.
Pol Maj Gen Thanit Jirananthawat said the combined effects of the various drugs, which together harm human organs, can easily be fatal.
Meanwhile, Metropolitan Police Bureau chief Phukphong Phongpetra on Tuesday gave an update regarding investigations into the ketamine that has so far killed seven people.
Pol Lt Gen Phukphong said that six of them were believed to have died immediately after taking the drug.
These cases are being handled by Wat Phrayakrai police station.
The seventh case is being investigated by police at Suttisarn station.
According to the initial autopsies, the victims died of heart and respiratory failure.
However King Chulalongkorn Memorial Hospital and Ramathibodi Hospital will investigate this further. The cocktails are usually concocted to enhance the effects of ketamine, Pol Lt Gen Phukphong said.
He said the source of this ketamine cocktail has not yet been found. All that is known is that it was sold in the area under Wat Phrayakrai police station and that some information regarding dealers has been reported. Police are currently hunting for them.
A young woman has been arrested in Bangkok's Sai Mai area and a quantity of the ketamine cocktail known as "k-powdered milk" has been seized.
Sirikarn Chuekhetkram, 23, was taken into custody in front of a house in Jitpawan community in the Sai Mai area on Tuesday after police acted on a tip-off by an informant alleging she sold the drug cocktail, known as "k-nom pong" by Thai users.
The police team, led by Metropolitan Police Division 2 chief Pol Col Saksit Meesawat, searched the woman and found three small plastic bags containing the drug in her pockets.
She allegedly confessed there were three more packets of the same drug in her bedroom. She took them there and police found the packets.
Ms Sirikarn told police the drug mixture contained ketamine and a sleeping pill called rosé (ramelteon, commonly prescribed under the brand name Rozerem).
Police claim Ms Sirikarn said she bought the drugs from a friend in Pathum Thani province's Lam Luk Ka district for 470 baht a gramme and sold them on Facebook for 600 baht a gramme.
Her regular customers were allegedly young people in the Sai Mai area.
Police said she also admitted to having sold the drugs over a long period before being caught.
Ms Sirikarn was initially charged with illegal possession of Category 2 drugs with intent to sell. She was taken to Sai Mai police station for legal action.
On Monday, national police chief Pol Gen Suwat Jangyodsuk ordered a crackdown on the new illegal drug cocktail following the spate of deaths.
Pol Lt Gen Phukphong said apart from the arrest of Ms Sirikarn, an investigation is underway to find others who could have been behind the sale of the ketamine cocktail.
A police source said on Tuesday that the Southern Bangkok Criminal Court has approved warrants to arrest four people allegedly involved in the selling of the ketamine cocktail at night entertainment spots in Bangkok.
The source also said Pol Lt Gen Phukphong has ordered police investigators to find more victims who took the ketamine cocktail and it has found that another 11 people were harmed by the drug; three were hospitalised, eight were taken to hospital emergency rooms and had to be examined by doctors.