Damien Bendall, 32, had previously denied murdering his then partner Terri Harris, 35, her 11-year-old daughter Lacey Bennett, her 13-year-old son John Paul Bennett, and Lacey's 11-year-old friend Connie Gent, but admitted their manslaughter.

Warning: This article contains details of the killings that some people may find disturbing

Bendall made his latest plea as he appeared at Derby Crown Court on Wednesday, where he also admitted raping Lacey after previously denying the charge.

Lacey and John Paul were Ms Harris's children from a previous relationship, and Connie had been at the house in Killamarsh, near Sheffield, for a sleepover when the murders took place.

Bendall is believed to have gone around the family home looking for his victims individually, and then attacking them in different rooms in order to kill them, the court heard.

He murdered the four victims at the house he shared with Ms Harris in what prosecutor Louis Mably KC told the court were "brutal, vicious and cruel attacks" on a "defenceless" woman and three children.

Mr Mably said Bendall attacked them with a claw hammer which he used to hit them over the head and on the upper body.

"Their skulls were smashed in" and "it was perfectly clear none of the victims stood a chance," Mr Mably added.

He continued: "One of the dreadful facts about this case is that during the attacks, the defendant raped 11-year-old Lacey."

Ms Harris and the three children were found dead in Chandos Crescent on 19 September last year.

In a police interview after he was arrested, Bendall told officers at Ripley police station: "I used the hammer."

He added: "Bet you don't usually get four murders in Killamarsh do you - well, five (murders), because my missus was having a baby."

Mr Mably said: "On the night of Saturday September 17, 2021, stretching into the early hours of September 19, the defendant brutally and viciously murdered his then partner, Terri Harris, who is aged 35 - and was in the early stages of pregnancy.

"He also murdered Terri's two children, by a previous partner, her 13-year-old son and 11-year-old daughter Lacey, and he murdered Connie Gent, also aged 11.

"She was a friend of Lacey's who just happened that evening to be staying at Lacey's house for a sleepover."

Bendall is due to be sentenced later today.

Mr Mably told the judge, Mr Justice Sweeney, that the Crown would be seeking a whole life term for Bendall, given the gravity of the offences.