Call that exposed killers: 'I want you to know I know Herman very well'

Herman Rockefeller's double life was exposed as police hunted for his killers. Photo / News Corp Australia

It was the call that busted the case of murdered businessman Herman Rockefeller wide open, and blew the lid off his secret life in the process.

It was the call no wife wants to receive, and no anonymous mistress wants to make.

But with a millionaire businessman missing, and police with no leads, it had to be made. So Rockefeller's mistress picked up the phone.

"Hello Vicky, you don't know me but I'm calling you about Herman," she began.

"I'm calling you because Herman called me on the night he disappeared. I want you to know that I know Herman very well."

The seriousness of the Melbourne businessman's disappearance meant "normal boundaries" had also disappeared, the mistress explained, revealing her 27-year on-and-off affair with Rockefeller.

And it's one of several which eventually led police to Rockefeller's killers, exposing along the way a trail of secret meetings, sex romps and swinging at odds with his public face of respected wealthy businessman and churchgoing family man.That explosive call, revealed in a new Australian true crime show Murder Calls, came hours after Rockefeller's distraught wife, who was raised in Otago, made an appeal via radio for information about her husband's disappearance.

Rockefeller had close links to New Zealand. He was chief financial officer of Brierley Investments in New Zealand for eight years from 1992 to 2000, after meeting his wife Victoria here in the 1980s, AP has previously reported.

He left Brierley when the company re-located to Singapore and was the buyer in 2003 of a six-level block in Petone for $3.5 million.He was also a director of biotech company Genesis Research, and had a holiday house in the Otago town of Karitane, 40km north of Dunedin.

He was also a friend of former Prime Minister John Key, according to the Otago Daily Times.

Murder Calls retraces the case which transfixed Australia, taking the viewer through the police investigation, focusing on the phone calls that cracked the case in the wake of Rockefeller's disappearance in January 2010.

On that night, he'd told his wife he was due to fly into his hometown of Melbourne at 10.30pm.

He always let her know what he'd be up to. So when he wasn't home by midnight, his worried wife rang police.

So began the heartbreaking hunt that would become one of the most bizarre murder cases in recent history.

Murder Calls retraces the search for the killers, taking viewers inside the investigation, using the phone calls which would ultimately see Mario Schembri, 57, and Bernadette Denny, 41 charged with his murder.

The trio's lives had collided after Rockefeller advertised in a swingers' magazine for a couple to have sex with. They had met once before, but the second meeting left Rockefeller dead.

Schembri and Denny would eventually plead guilty to manslaughter.

An argument had broken out at their home, and ended, Schembri told the court, when he punched Mr Rockefeller "harder than he had ever struck anyone before", and Rockefeller fell, and hit his head and died, the court heard.

Revisiting the investigation, via interviews with police, the phone calls and using crime scene footage and key interviews, Murder Calls details first the battle to find Rockefeller's car, following the revelation he'd flown into Melbourne an hour earlier than he had told his wife he was due, and was last seen leaving the airport.

"Heard you're looking for a blue Toyota Prius. I think it might be out there in Carween Lane, out near Des Conroy's," crackles Craig Smith's voice.

As the search continues, Mrs Rockefeller's public appeals reveal a woman as puzzled by police as to why her husband has disappeared.

"I mean, I hear all his telephone conversations," she said during one appeal for information.

But his mistress knew differently, telling her Mr Rockefeller had four other mobile phones he carried.

Ultimately, it was those secret phones that would lead him to his death. And lead police to his killers.