The arrest of two suspects who confessed to killing two Russian siblings in Chon Buri has led to another tragic discovery involving a Thai family of three who had been reported missing two months ago.

Ex-convict Thana Kerdthong, 43, and Thongchai Srinil, 39, who were arrested in Sa Kaeo on Friday, were taken by police to the burial site of the young Russians in Chon Buri later that night.

The site was in a forested area in tambon Huai Yai of Bang Lamung district, about two kilometres from where the killings took place, according to Pol Lt Gen Chatchai Surachetphong, commissioner of Provincial Police Region 2.

The bodies of Diana Nazimova, 22, and her brother, Roman Nazimov, 17, were found buried together in a grave about one metre deep. They had been missing since July 26.

The older sister, whose body was found on top, showed signs of physical assault. Her brother had been shot once in the head and once in the abdomen.

Both victims were found lying on the ground without being wrapped or concealed, and were still fully clothed.

A preliminary examination found no evidence that the female victim had been sexually assaulted, police said.

Suspect admits to another killing

Nearby, officers found the bodies of a father, mother and daughter buried together in a single grave in a coconut grove.

It turned out that Thana, one of the suspects in the slaying of the Russians, had confessed to killing the family, who also lived in Bang Lamung, claiming the motive was robbery.

Investigators subsequently arrested two other suspects, identified as Chatchanan Paen-aiam and Atsadang Chuwong.

According to the confession, the suspects went to the victims’ house posing as police officers and handcuffed the husband and wife, who were the only people home at the time.

The couple’s daughter later returned from a convenience store and was restrained. Investigators said the suspects then took all three to another location, shot them dead and buried their bodies. (Story continues below)

Reporters crowd around one of the suspects held in the slaying of two Russian siblings as he is escorted by police on Friday night.

‘Family might never have learned their fate’

The younger sister of the slain woman, who gave her name as Tukta, broke down in tears as she spoke to reporters on Friday night, saying the family had desperately searched for her sister, brother-in-law and niece after they disappeared.

She said the family’s car, motorcycle and other belongings were still at the house in Bang Lamung, with no signs of a struggle or the property having been ransacked.

For more than a month, relatives continued bringing food to a dog at the house and repeatedly called the family’s mobile phones, but none of the calls was answered.

Ms Tukta said they had done everything possible to locate the missing relatives, including filing a missing persons report, coordinating with police and contacting mobile phone service providers.

However, they were unable to obtain some information because such requests could only be made by law enforcement authorities.

She said that had police not investigated the murders of the two Russian siblings, the family might never have learned the fate of her sister, brother-in-law and niece.

Police are continuing to verify Thana’s statements and investigate whether he may be linked to other crimes.

Prime Minister Anutin Charnvirakul on Saturday cancelled his afternoon engagements in Suphan Buri and said he would instead travel to Chon Buri to follow up on the murder investigations.

He said the brutal killings were tantamount to “killing the entire nation” because they had damaged public confidence and tarnished the country’s reputation.