A City banker who bludgeoned a woman to death with a pestle has been jailed.
Zahid Naseem, 48, killed Christina Abbotts at a flat in Crawley, West Sussex, in May, after paying for her services as a high-class escort.
Judge Christine Laing said Ms Abbotts would have experienced "unimaginable terror" during the attack, which was of "extraordinary ferocity".
Naseem was convicted of murder after a trial at Lewes Crown Court and jailed for life with a minimum of 19 years.
Jurors heard Ms Abbotts had suffered more than 13 wounds to her head and 20 other injuries.
Naseem, of Amersham, Buckinghamshire, stayed in the flat for 12 hours after killing Ms Abbotts, 29, and pretended to be unconscious when police arrived, the court heard.
He had claimed he was acting in self-defence after Ms Abbotts tried to strangle him during a sex game, but the judge rejected that suggestion.
Ms Abbotts' body was found by police when they were called to the flat, where she had been house-sitting, when she failed to turn up to her own birthday party on 25 May.
Naseem was found lying motionless on the sofa, but paramedics were "sceptical" he was unconscious. He later told officers he had no idea what had happened.
Ms Abbotts, who was born in the West Midlands, was described in court as a "socialite" who led a party lifestyle in London.
She told relatives she worked in IT, but advertised her services as a high-class escort online under the pseudonym Tilly Pexton, the court heard.
Naseem paid her up to £3,500 a time when they met.
Judge Laing told Naseem: "When I consider the extent of all the injuries, you inflicted considerable pain.
"The terror of her final few moments of life is unimaginable."
She said Naseem had "shown not one jot of genuine remorse," adding: "You are full of self pity but have no understanding of the true nature of what you have done."
The judge said Ms Abbotts, as an escort, "had chosen to earn her money in a business that is as old as time" which "carried with it huge risks of danger, as this case sadly demonstrated".
Naseem had become addicted to drugs and alcohol and became "obsessed" with escorts, Judge Laing added.
'Fall from grace'
Lewis Power QC, defending, said Naseem had once held "high status" as a risk analyst in the City but was experiencing work problems and a deteriorating personal life at the time of the killing.
"He's now fallen from grace in the most dramatic of manners," Mr Power said.
Ms Abbotts was described by her family as "petite, happy and well-educated".
In a victim impact statement, they said they had been "hoping one day to walk her down the aisle, she would have been such a beautiful bride, and instead we had to take her in a coffin".