Ilan, who died from COVID-19 last October, gave an interview two months prior to his death to Shadow of Truth, an award-winning Israeli documentary series following the 2006 murder case of Rada and the subsequent trial and conviction of Zadorov.
Zadorov, convicted in 2010 and again in 2014 of murdering the 14-year-old girl at the Nofei Golan Middle School in Katzrin, has been the subject of great controversy and speculation, as doubts have been raised regarding his guilt.
Even Rada's mother, Ilana, has publicly stated that she believes Zadorov was wrongly convicted.
Former Supreme Court deputy chief justice Hanan Melcer announced in May that he has approved the request for a retrial for Zadorov.
Next week, state attorney Amit Eisman is set to give his verdict on whether to hold a retrial or to dismiss the charges against the controversially convicted man.
"Zadorov fell in the corrupt police officers' trap. The interrogators, in cooperation with the prosecution, framed him," Ilan said in the interview, adding that "the police aren't willing to admit it."
"I have heard a countless amount of real and false confessions: I can differentiate between the two," he said.
"It's possible that an innocent man is sitting in prison. It took me two years to go through the entire case and I came to an unequivocal conclusion – Roman Zadorov is innocent," he claimed, according to N12.
According to the report, Ilan spoke in detail on how he came to this conclusion.
"There's only one way to tell a real confession from a false confession: concealed information," Ilan explained.
"Zadorov's confession was filled with false concealed information," claimed Ilan. "Out of 40 different pieces of detail he gave the interrogator, he only correctly guessed one - Tair's locker number.
"Zadorov begged for the police to look for the pair of pants he supposedly threw away, to prove there were no blood stains. They found eight pairs and found no blood stains," Ilan noted.
"They destroyed them all, without showing Zadorov what they found. They destroyed evidence," he claimed.
Ilan also commented on sections of audio being muted during Zadorov's interrogation, according to the report.
"It baffled me. That doesn't happen. These weren't mishaps as they [the prosecution] stated in court – they were initiated pauses," Ilan said. "I know that for a fact, as I know the insides and outs of control rooms," he also claimed, according to N12.
The television news also reported on the prosecution's response to Ilan's reported claims.
"Ilan's claims were examined over and over," the prosecution reportedly responded. "In former Chief Justice Melcer's approval of a retrial, he did not accept Ilan's opinion on the matter."