It took six minutes for the Greek husband of Caroline Crouch to smother her to death with a pillow, investigators have concluded from information gleaned from her smartwatch.

Data measuring her heartbeat showed that the young British woman, who grew up in Greece, was asleep when she was attacked by her husband in the early hours of May 11 at their home in Athens.

The couple had argued the evening before and Ms Crouch had threatened to leave him, taking their 11-month-old baby girl Lydia with her.

At 4.05am her heartbeat suddenly increased, suggesting “an extreme state of mental or physical stress,” according to the Greek coroner.

It remained at a high level until 4.11am – six minutes later. Her heartbeat then went dead.

Ms Crouch, 20, suffered a “distressing” death, the Greek coroner concluded.

Babis Anagnostopoulos leaves court in Athens escorted by police after confessing to killing his British wife Caroline Crouch

Credit: Getty

“The process of death lasted a few minutes, it was not instantaneous,” the coroner said in a report.

“The final recording on the smartwatch is at 4.11am and I believe that death occurred immediately afterwards.”

Babis Anagnostopoulos, 33, a helicopter pilot, claimed that his wife was murdered by a gang of three armed robbers who broke into their apartment in the middle of the night, tied him up and taped up his mouth and then suffocated his wife to death.

He maintained his story for more than a month, providing compelling details, such as his claim that he had to use his nose to dial emergency services on his mobile phone because he was bound with rope.

But it was a web of lies – on Thursday, just hours after attending a memorial service in honour of his wife on the Aegean island of Alonissos, where she grew up with her British father and Filipina mother, he confessed to the murder following a six-hour police interrogation.

Caroline Crouch met her future husband when she was still in her teens

Anagnostopoulos was charged with murder on Friday and remains in custody. He is due to appear in a court in Athens next week to give evidence.

Extracts from Ms Crouch’s diary, obtained by the Greek media, showed that the couple had a tempestuous relationship. They had met on Alonissos when Ms Crouch was just 16.

In 2019 she wrote: “We fought last night because I had a meltdown because of my hormones. I yelled at him and hit him and told him I don’t want our baby… I am not well, I am very upset.”

In July she wrote: “Today my little one is a month old. It’s also the day I told Babi I want to leave. I feel awful.”

She had contemplated leaving Anagnostopoulos before she became pregnant but then decided that she did not want their child to grow up without a father.

On the night of her death, Ms Crouch had told him she wanted to leave and data from her mobile phone showed that she had been searching for a hotel room to book.

Asked why it took Anagnostopoulos 37 days to confess to the killing, his lawyer claimed that his main concern had been for his baby daughter. “He did not want to deprive the child of both parents on the same day,” said Alexandros Papaioannidis.

“That is what he was thinking and so he did not immediately confess to the murder.”

In a statement released through his lawyer, Anagnostopoulos said: “My concern is for our child, Lydia. I am devastated about everything I did.”