A MAN arrested on suspicion of strangling his two children in Manchester, England, is Zimbabwean.

Petros Mwashita, also known as Williams, had taken an overdose when his estranged partner Morongoe Molemohi – a Lesotho national -- walked in on the grim scene on Wednesday morning, police said.

Mwashita, 37, was discovered on his bed alongside son Theo Molemohi, two, and daughter, Yolanda, four, who had both been strangled with lengths of cord.

It is feared churchgoer Mwashita – who was granted asylum in the UK -- hatched a monstrous plot to "punish" his devout Christian partner, Molemohi, for splitting up with him.

Molemohi made the horrific discovery after calling to pick up belongings from the flat in Whalley Range, Manchester. A post mortem carried out on Wednesday night confirmed that Theo and Yolanda had been strangled.

Mwashita, who is under arrest on suspicion of murder, had taken an overdose of prescription tablets. He collapsed soon after his arrest and was taken to hospital.

Molemohi, 30, had left the family home in Lansbury House -- a three-storey housing association block of flats in Whalley Road -- with the children seven days ago after the marriage broke down.

She had been re-housed by Manchester council's homeless unit and was living in a bed and breakfast. The children had been staying with their father for a few days.

Molemohi arrived at 8AM on Wednesday and found their lifeless bodies. Theo was already dead and paramedics tried unsuccessfully to revive his sister on the way to hospital.

Molemohi, described as "extremely distressed", was placed under sedation at Trafford General Hospital.

It is believed that Mwashita had struggled to come to terms with the breakdown of his relationship. It is understood that nobody else was involved in the split.

Mwashita remained in hospital on Thursday where he was undergoing treatment for the overdose, as well as having a psychiatric assessment carried out.

Molemohi, a PhD student from Lesotho, had asked for permission to stay in Britain. Both children were born in England.

Det Supt Geoff Wessell said detectives were not seeking anyone else in connection with the deaths.

Wessell said: "This was a traumatic incident for the family and the officers that attended. No other person is being sought in connection and the male arrested remains in custody and is due to be interviewed."