His father today said he tore the letter into about six pieces before putting some of them in the house bin and some into a bin at a petrol station.
He said his wife, Anita, 51, found the letter on May 11 last year after police let the family back into their home in Bournemouth, Dorset, following Emily's death.
Wearing a grey checked suit, he told Winchester Crown Court: "When we got back home it had been left in a mess by police so we decided to do a clean up.
"Anita brought me some paperwork and among it was a plain white envelope. I ripped the corner and saw it said 'dear mum.'
"I recognised the writing, it was my son's.
"Stupidly, I ripped it up. I just thought the worst case scenario might have happened.
"I didn't know what it said. It might have said Elliot had some involvement with Emily's death.
"I had a million and one thoughts in my head, I was numb. It was a horrendous feeling, as if I was burning inside.
"I didn't want to read what it said, I didn't want to know.
"I know it sounds awful but I ripped it up.
"I did destroy it but not to pervert the course of justice."
Turner's barrister Robert Gray asked him why he was heard saying to his wife on a covert recording made at their house: "We're perverting the course of justice.
"I know I should not have destroyed that letter. That was a confession. He f***ing strangled her."
Turner said he had said it was because he "always assumed the worst" and sometimes "just talked nonsense."
Turner, whose family have owned R E Porter jewellers in Bournemouth for about 30 years, admitted he had been having relationship issues with his wife and the couple had been sleeping in separate beds.
FATHER DESCRIBES FINDING EMILY
He also said he "could not recall" what was said in a two minute phone conversation he had with his son while rushing home from work after Anita told him Emily was dead.
He said: "I went into Elliot's bedroom and just saw her laying on the bed looking like she was asleep.
"I knelt down and touched her hair and started crying.
"I touched her cheek and it was cold, like crisp ice.
"I said 'you remind me of a butterfly. Sorry, butterfly.'
"Anita rang the paramedics and Elliot was standing in the doorway with his suitcase.
"He said he was going to Spain and I said 'don't be silly, you've got nothing to run from'.
"I said 'you're not going anywhere.' Then there was an eerie silence, it was an accepting of the situation."
FATHER DESCRIBES SON'S 'GODDAMN GANGSTER BRAVADO'
Today Leigh Turner broke down in court as he criticised his son for his "goddamn, bullshit, gangster bravado."
Turner was in tears while secret recordings of his son were played trying to convince Mrs Turner to change her story.
He told the court "Elliot thinks he's the big 'I Am'" and described him as "just a stupid clown."
Turner added that he had "an image he portrays to impress the stupid oiks he mixes with."
The tapes reveal his son trying to convince Anita to change her story as he tells her "if you don't you will be charged and in the s***."
He is also heard telling his parents he "had never felt such anger" in the month leading up to Emily's death.
Turner said: "It's horrible to say, but that's typical Elliot, that goddamn, bullshit, gangster bravado.
"He does it to get back at me because of the way things are between me and his mum.
"He's not someone who gets angry, he's a stupid clown.
"Obviously he was upset because of the things he found out about Emily on Facebook and Twitter but he's not some angry gorilla."
Mr Mousley asked him what motion his son made during one of the recordings when he demonstrated how he grabbed Emily in the fight they had before she died.
When he put up two arms, Mr Mousley said "careful, that looks like a sleeper hold" to which Turner replied "with all due respect, I know you're doing your job, but that is not fair and nothing like a sleeper hold."
ELLIOT TURNER PLEADS GUILTY TO PERVERTING COURSE OF JUSTICE
Elliot Turner today admitted asking his mother to lie to police and changed his plea to guilty to perverting the course of justice.
He was arrested following Emily's death on May 7 last year but then released on bail and police bugged the 350,000 pounds Turner home in the affluent Queens Park area.
The jury has heard they recorded the family talking about "fabricating evidence and being worried about lying to police."
Under cross examination, Turner was asked about recordings in which he is heard asking his mother to change her evidence.
Police scans of computers seized from the home also found Google searches for 'death by strangulation' and 'how to get out of being charged for murder.'
The three family members were arrested and charged in July last year.
Elliot Turner denies murder. His parents both deny perverting the course of justice.
Emily was born in Britain but her family emigrated to New Zealand when she was nine and she was raised in Auckland.
She had returned to live with her grandparents in Bournemouth, to study for a business national diploma at Brockenhurst College, Hants.
She was also signed up to a modelling agency and had appeared on the front page of a magazine in New Zealand.
The trial continues.
