Father 'strangled his two children with internet cables after discovering wife had used online dating website' Last updated at 5:56 PM on 22nd March 2010 A jealous husband strangled his two young children with internet cables after he discovered his wife had been using online dating websites, a court heard. Petros Williams, 37, was angry and bitter when his wife Morengoe Molemohi left him after the breakdown of their relationship. A jury was told he recorded a haunting video of his two children laughing and waving goodbye to their mother. Loss: Brother and sister Theo Molemohi, aged two(right) and Yolanda Molemohi, aged four(left) were found by their mother He labelled the video 'The End' and two days later he allegedly strangled four-year-old Yolanda and two-year-old Theo Molemohi with internet cables in a 'symbolic act of punishment.' Andrew Thomas, QC, prosecuting, said the couple had separated in September last year and his wife, who was known as Mo, had begun exchanging messages with other men on internet dating websites. She had moved out of the flat they shared in Whalley Range, Greater Manchester, but returned daily to get Yolande ready for school and to care for Theo while Williams went to work as a finance officer for a housing company. Mr Thomas said: 'On Tuesday 13th October, Miss Molemohi left the children with the defendant and returned to the hotel where she was staying. 'The next morning she went back to the flat to help get her daughter ready for school. The front door was locked from the inside. She had to let herself in through the patio windows. She found the defendant in the bedroom. He was lying on the bed with the two children. Scene: Bodies were found at a block of flats in Whalley Range, Manchester 'Miss Molemohi thought the two children were asleep. It was only when she reached out to them she realised they both had cables tied around their necks. 'The prosecution say that the use of the internet cables to kill the children apears to have been some sort of symbolic act of punishment.' The court heard Miss Molemohi screamed and rang 999 where she told an operator: 'My husband has killed my children.' Mr Thomas said: 'There were notes in the flat. They were, in effect, suicide notes, saying goodbye to his wife and colleagues. 'If the defendant had intended to kill himself, he had not got very far. He was still very much alive although he appeared unwell. 'The defendant killed his two children. It was a spiteful and selfish reaction to the breakdown of his marriage. It was a deliberate act and the prosecution say it was murder.' Manchester Crown Court heard Williams left a sarcastic message attached to the computer which read: 'Mo, use the internet as much as you like, luv Petros.' The jury was told Miss Molemohi, a pay clerk, had met Zimbabwean-born Williams in 2000 when the pair were both studying in South Africa. They married and moved to the UK in 2002 after Williams was granted asylum. But the court was told there had been difficulties in the relationship for years Miss Molemohi contacted Womans Aid after Williams tried to strangle her in July 2009. Mr Thomas said: 'By September, Miss Molemohi was actively looking for other men on dating websites. She wasn't secretive about that. On occasions, she deliberately left the sites visible on the home computer so that her husband could see what she was doing. 'The defendant was not prepared to let her start a new relationship while she was living in the same property, and, at the start of October, asked her to move out of the flat.' The court was told that Williams had contacted two men his ex-wife had contacted online warning them to stay away from her. Williams, who denies two counts of murder, showed no emotion as the jury were shown a home video labelled 'Daddy, Yolly and Theo. The End video.' The video, recorded as the children watched X-Factor on the Sunday night before they were killed, shows them waving at the camera saying: 'Goodbye mummy.' A note found in the flat read by the video camera read: 'Play the video we made for your memories. Thankyou Petros.