A multi-millionaire British businessman has admitted killing his girlfriend during "rough sex" at their home.

John Broadhurst (40) was cleared of murdering Natalie Connolly and causing her grievous bodily harm on the directions of the judge following legal submissions part-way through his trial.

The father-of-three admitted manslaughter by gross negligence after leaving his girlfriend to die at the foot of a staircase.

Prosecutors had alleged that Broadhurst "totally lost it" during drink and drug-fuelled intercourse at their home in Staffordshire.

It was heard during the opening of the trial that the couple had "rough sex" on the night of Miss Connolly's death.

The 26-year-old was found with more than 40 injuries.

Broadhurst failed to contact the emergency services in circumstances where "a risk of death as a result of her condition would have been obvious", the court heard.

David Mason QC, prosecuting, explained the decision to allow the property developer to admit to a lesser charge.

He told the court: "The evidence in this case, which is an extremely unusual case, has been very complicated.

"The family (of the victim) have been consulted and are entirely content with the view that the prosecution have taken."

Broadhurst, said to have a fortune of around stg£15m, had separated from a former partner, who was pregnant with their second child, around three months before Miss Connolly's death.

Miss Connolly, who had suffered a "blow-out" fracture to her left eye, bruising and internal injuries, had told trial witnesses that she and the defendant had an interest in masochistic sex, the court heard.

A paramedic told the trial that Broadhurst appeared hungover and did not seem "unduly upset" after finding his partner's body at about 9.30am.

The businessman, who has since moved to Wolverley, Worcestershire, will be sentenced on Monday after being granted bail.

Mr Justice Julian Knowles, adjourning the case, told Broadhurst: "You have pleaded guilty to manslaughter.

"Whilst it is not a charge of murder, it is nonetheless an exceptionally serious offence.

"All sentencing options remain open. You should be prepared for a custodial sentence of some length."

Detective Inspector Victoria Downing, of Staffordshire Police, said after the hearing: "Natalie was callously and cold-heartedly left fatally injured at the bottom of the stairs by Broadhurst.

"Yet he didn't call for help until 9.30am and then showed total disregard for what he had done when he spoke to the emergency services."