Speedboat killer Jack Shepherd has lost a Court of Appeal challenge against his conviction for the manslaughter of 24-year-old Charlotte Brown.
He was jailed for six years over the death of Ms Brown, who was thrown from his boat when it capsized on the River Thames during their first date in December 2015.
The 31-year-old web developer challenged his conviction for manslaughter by gross negligence at the court in London last week.
His lawyers argued the conviction was unsafe because some of the evidence at his trial came from an interview during which he was not cautioned or offered a solicitor because of a “mistake” by police.
But his appeal was dismissed by Sir Brian Leveson and two other senior judges on Thursday.
“When granting leave (to appeal), the single judge made the point that the appellant should not be overoptimistic as to the outcome,” said the judge.
“That warning was prescient. The appeal against conviction is dismissed.”
Shepherd was criticised by Charlotte Brown’s family after the appeal hearing.
Ms Brown's sister Katie said Shepherd had “not once shown any remorse or respect to our family, or to the legal system or to even Charlie".
Shepherd, originally from Exeter, went on the run ahead of his Old Bailey manslaughter trial and was convicted in his absence in July 2018.
He was later extradited to the UK after being captured in the former Soviet Republic of Georgia after handing himself in to police in the capital Tbilisi in January this year.
Jurors at his trial heard that he and Ms Brown, 24, from Clacton-on-Sea, Essex, had been drinking champagne and went on a late-night trip in his boat past the Houses of Parliament.
It was claimed that Shepherd handed the controls to Ms Brown just before it struck a submerged tree and overturned, tipping both of them into the water.
He was plucked from the Thames alive, but Ms Brown was found unconscious and unresponsive.