It could have been a plot from an Agatha Christie mystery.

A man spends a pleasant morning drinking with a friend, gets a wedding proposal from his girlfriend and then the couple leave.

As the groom-to-be walks away, his sweetheart notices he has a knife sticking out of his back...

But none of the three – not even the victim – knows how it got there.

But now a jury at Canterbury Crown Court has added to the baffling whodunnit by deciding it was not Ramsgate man Anthony Hayward... in his living room in Brunswick Court, Hardres Street... with the kitchen knife.

Mr Hayward, 69, was the only person charged with the stabbing – and after the not guilty verdict the police have now closed the file.

The three-day trial heard how 42-year-old victim Wayne Elliot, of King Street, Ramsgate, was so drunk - after sharing two bottles of vodka for breakfast - that he did not even know he had been stabbed.

And after less than one hour's deliberation, the jury acquitted Hayward of wounding his friend – who was nicknamed Bonzo- with intent to cause him serious harm.

Prosecutor John Fitzgerald said in October last year, Mr Elliott had telephoned the man he regarded as a father figure after downing a bottle of wine overnight.

He was invited to Mr Hayward's home – arriving at 10am – where the two polished off a bottle of vodka, which had been a birthday present from Mr Hayward's son.

During their chat, Mr Elliott received a text message from his girlfriend, Maria Tantony, 50, asking him to marry her – and she arrived around midday after Mr Hayward bought another bottle of vodka and a bottle of gin.

At some point in the afternoon, Mr Elliott and Mr Hayward both fell asleep – and when they awoke, Mr Elliott had a knife - which had been used to cut lemons for the drinks - sticking out of his back.

Police arrived to find Mr Elliott lying over the coffee table – with the weapon still in his back, shouting: "Just pull it out, just pull it out!"

The victim was then taken to hospital where the knife was later removed from the side of his spine by surgeons and Mr Elliott made a full recovery.

He later told police he did not believe either his friend or his girlfriend would have stabbed him.

And he told the jury: "I fell asleep and the next thing I remember I was in hospital. I seriously can't remember how the knife got in my back.

"When I was told Mr Hayward and Miss Tantony were in custody my jaw dropped. I can't remember nothing about what had happened."

“I woke up and Bonzo was next to me on the settee... there was a knife sticking out of his back. I don’t know how it got there” - Anthony Hayward

Detectives discovered a blood stain on Mr Hayward's trousers and a small cut to his little finger – Ms Tantony initially claimed strangers had arrived and forced their way into the flat.

She later retracted that statement, but was never charged with any offence – and was never called to give evidence at the mystery stabbing trial.

And in a recording of a 999 call to the ambulance service, the prosecution claimed Mr Hayward said: "I've just stabbed a bloke in the back with a knife!"

But he told the jury he was drunk and thought he said: "There is a bloke who has just been stabbed in the back with a knife."

He said he got on well with Mr Elliott and the two "liked a drink" – meeting sometimes in the morning.

"Bonzo looked upon me as a father figure," he said. "He called me that morning and said he was hanging off. I took that to mean he had a hang over.

"Bonzo had called me the night before and said he had fallen out with Maria because he thought she had been flirting with another person in the pub. They had a row in the pub."

Mr Hayward said "Bonzo" had received a text from Ms Tantony asking him to marry her – and he offered to lend his friend a jacket and tie so he could be wed.

He told the jury: "I woke up and Bonzo was next to me on the settee... there was a knife sticking out of his back. I don't know how it got there, but I didn't stab him."