The allegations came to light after Scott Rogers, 52, a former dance academy teacher in Suffolk, UK, was shot at his home in Iberville, Louisiana.
|Scott Rogers on set of 'Around Town' on WAFB-TV|
Computers and mobile phones have been seized from Mr Rogers' house as part of the investigation into his death.
The Iberville sheriff's office said the WAFB-TV presenter was thought to have been shot by former lover Mathew Hodgkinson - also his son-in-law - who they believe then shot himself in the head.
Mr Hodgkinson, 36, who was married to Mr Rogers' daughter Kimmy, remains in hospital in an induced coma but has started to show signs of life.
On Tuesday he was seen to move and deputies are confident he has brain activity, reports WBRZ News 2.
One said he was aware of allegations made against Mr Rogers by the age of 12 and said he began becoming "intimate" with him when he was 13.
"The truth is... when I met that man I was 12 years old... he was introducing concepts like love to me, through sex he was informing my understanding of physical intimacy," the man said. Good grief!
"He would guide me in how to speak to my parents on what to say to people. I'll bet.
Police at the Scott Rogers' property
|"Other accusations came up... not totally resolved when he left England and |
I think that past history was catching up," Sheriff Brett Stassi told WBRZ
Mr Rogers is thought to have failed to declare the fact he had been arrested in the UK when applying to become a foster parent in the US.
A second British man told the radio show that Mr Rogers was "a master manipulator, an expert at brainwashing".
He said: "He is the worst predatory paedophile that you could imagine and when you are a child and you are faced with that type of monster with that type of intelligent mind, you don't stand a chance."
|The show that Rogers hosted on WAFB|
Around Town TV Show logo
"People here are in shock," said Sheriff Stassi. "They knew his TV persona, he would donate all of his time to help with things that were meaning a lot to people over here."
Sheriff Brett Stassi, of Iberville police, told the BBC: "My concern is just with the murder-suicide at this time.
"If some of these computers or phones open up to some child pornography or something we'll go in that direction - but we have no evidence of that as this time.
"All I can say is the life he left in the UK was among a conversation of sexual abuse - but not here.
"It was only before the continued custody hearing we heard for the first time why he left the UK."
The abuse is alleged to have happened in the UK in the early 1990s.
Mr Rogers, then 28, was arrested by Suffolk Police following an allegation of sexual assault against a 13-year-old boy in June 1991 at the Bury St Edmunds Academy of Dance, Suffolk Police said.
In May 1992, he was charged with a number of sex offences and in June 1993 stood trial at the Inner London Crown Court, where a jury failed to reach a verdict.
The judge discharged the jury and no retrial took place, meaning Mr Rogers was acquitted.
He left the UK in the mid-1990s after the arts academy he founded in Bury St Edmunds was likened to a "cult".
|Scott Rogers circa 1994 and exterior view of dance academy in Bury St Edmunds|
There were claims of an "unhealthy atmosphere" similar to "a religious or supposedly religious cult" at the school founded by Mr Rogers, the East Anglian Daily Times has reported.
A Suffolk County Council spokeswoman said the council "was made aware before the fatal incident that services in Baton Rouge were investigating Richard Scott Rogers".
"Suffolk County Council and Suffolk Police are supporting and assisting those services," she said.
"We will be keeping this matter under review and if anyone would like to make contact about this case you can do by calling Suffolk Police."