A Thai father has been arrested over the alleged murder of five of his children after a two-year-old girl was found entombed in concrete under a kitchen floor.

Songsak Songsaeng, 46, and his wife Sunan Nahuanin, 40, reportedly beat to death the two-year-old girl nicknamed 'Model', then buried her body in Sunan's house in Kamphaeng Phet, Thailand in May.

The couple had told neighbours they had sent the girl to live with her grandfather in another province, but locals remained suspicious as they claimed to have frequently heard domestic violence in the household.

Model's demise came to light when social media influencer Kanthat Pongpaiboonvej, also known as Kan Chompalang, received a report from the residents that the husband and wife were abusing their two daughters aged 12 and 4.

Bang Khen district police raided the family's home in Bangkok to rescue the girls on September 10, but the couple had already fled the scene. The youngsters then told authorities that their parents had killed their youngest sister Model four months ago.

Officers launched a manhunt for the couple and caught them withdrawing cash inside a mall in Pathum Thani province just 25 miles away from the capital. The cops seized from them a Honda Jazz sedan believed to have transported Model's corpse.

Police grilled Songsak at the station until he allegedly confessed to killing Model. He and Sunan later took the officers to Model's burial site, where authorities excavated the body which was wrapped in three layers of rubbish bags dumped two feet underground.

Police Colonel Anan Vorasart, chief of the Bang Khen police, said: 'The couple have pointed out where they buried their daughter's body, in the kitchen area of the woman's house in Kamphaeng Phet. They are detained at the Bang Khen police station. We are continuing to investigate why they killed their child.'

Songsak reportedly claimed he felt guilty over his actions, which he said were influenced by 'mental illness'.

Songsak was reported to have fathered 10 children by four wives - one from his first, another from his second, five from his third, and three with his current wife Sunan.

He also allegedly admitted to killing four of his sons - all aged under one year - from a previous wife Jesada Meepien. The murders reportedly happened in 2013, 2014, 2016, and 2018, with Songsak disposing of the corpses in Bangkok's Bang Khen and Sai Mai districts.

Jesada claimed she could not report the alleged murders to the police as Songsak had threatened her into silence.

Police Major General Noppasilp Poonsawat, the deputy commissioner of the Metropolitan Police Bureau, said DNA testing was being conducted while police interrogated the rest of Songsak's children.

He added that they were reviewing Songsak's medical records to see if he had a history of mental illness.

Meanwhile, Sunan's mother Lamduan Nahuanin, 74, said she was shocked by the discovery as she did not think her daughter was capable of such barbarity.

She said: 'I am extremely saddened by what happened From now on, I will continue to raise my youngest grandchild until my last breath. As for the body of my 2-year-old grandchild, once the autopsy is completed, I will arrange for a funeral at the local temple.'