Norfolk farmer Tony Martin told police a man had tried to molest him at his old family cottage.
The revelation was made in the new Channel 4 factual drama The Interrogation of Tony Martin, which aired tonight, of police interviews made after he had shot dead a burglar at his home in 1999.
Nearly 20 years since he was arrested, viewers around the country were able to see and hear for the first time what he had told detectives just days after the shooting, based on verbatim tapes and transcripts.
He was sentenced to life in prison after he shot dead 16-year-old Fred Barras, after he broke into his remote farmhouse at Emneth Hungate, near Wisbech.
Barras's accomplice, Brendan Fearon, who was 30 at the time, managed to escape to the home of Mr Martin's neighbours Paul and Jackie Leet after getting shot in the thigh and buttocks.
Tony Martin is taken into question the day after the shooting, and is asked point blank 'did you shoot anybody last night?' - before police discovered Barras's body in his garden.
Mr Martin repeatedly told police: 'I really don't want to talk about this.'
He told police he never let anyone into his home, nicknamed Bleak House, after a series of previous break-ins left him fearful.
'Nobody comes into my house,' he told detectives. 'I'm not strange, I want you to understand why.'
He revealed a dark secret of his past, which he had not shared even with his mother Hilary Martin until four or five years before the time of the interview. 'I don't want this to go public,' he said.
'We had a small cottage over at March, there was a man, he used to stay with us.
'As I got older, I don't remember what age, I can't remember now, he used to try and molest me.
'And that's had a great affect upon my life,' he said. 'It made me very self conscious when I was a youngster.
'I've had that experience and it doesn't leave you, it's a scar, this is why, one of the reasons, I live on my own.
'Nobody ever comes into my house,' he repeats.
What captivated the nation was Mr Martin's insistence he had fired his unlicensed shot gun at Fred Barras in self-defence which sparked a debate on the use of reasonable force to defend property.
After being convicted of murder following a trial in Norwich Crown Court in 2000 and being sentenced to life, the conviction was later reduced to manslaughter and he was released in 2003.
Speaking exclusively to this newspaper just days before the TV drama was broadcast, Mr Martin said he has not set foot inside Bleak House since his release from jail.
At the end of the programme, Tony Martin is interviewed after being released from prison outside his boarded-up farmhouse.
The interviewer asked Mr Martin why he does not live in the house anymore, he alluded that he would defend himself again.
'If somebody comes into the house I'm going to look after myself,' he said.
'When you start to run you'll be forever running, you have to stand your ground.'
When asked whether Fred Barras's death weighed heavily on him, he said: 'I don't even think about it.'
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