EXCLUSIVE
The son of one of Australia's richest men and a leading biomedical research institute are embroiled in a legal battle over the estate of the late Sydney socialite Virginia Kahlbetzer.
John Igino Kahlbetzer, known as Johnny, has launched legal action in the NSW Supreme Court seeking a slice of his mother's estate for his "maintenance and advancement in life".
Mr Kahlbetzer, 49, is the son of German-born agribusiness baron John Dieter Kahlbetzer, whose fortune was estimated by BRW last year at $790 million.
He and his younger brother Markus run the family's extensive Australian agribusiness, property, venture capital and resources operations.
He lives with his wife Donna, who was married to former motorcycling champion Wayne Gardner, and their son Colt on the world's most expensive street, Avenue Princesse Grace, in Monaco.
He also owns Sydney's biggest residential waterfront property "Windermere" at 42 The Crescent, Vaucluse.
He took over the six-bedroom mansion after his mother vacated on New Year's Eve 1999. After separating from John Dieter in 1985 the estranged couple came to an arrangement in which she lived in the 6111 square metre property rent-free for 15 years.
Last month the Garvan Institute was joined as second defendant in the proceedings brought by Mr Kahlbetzer against the executor of his mother's will, Alexandra Virginia Holt.
After Mrs Kahlbetzer's death from lung cancer in August 2013 Mr Kahlbetzer and Ms Holt, who is his cousin, sold her stunning Rose Bay apartment for $4.1 million.
Mrs Kahlbetzer was a long-time supporter of the Garvan Institute of Medical Research and named a "Life Governor". In 2001 she began donating to cancer research and soon became the "major force" behind the institute's lung cancer team.
Her initial five-year pledge, made in memory of her father who had died of lung cancer, was expanded to include colon cancer.
In a tribute to Mrs Kahlbetzer on its 50th anniversary, the Institute said: "Her donations often came quite unexpectedly, were most timely and provided enormous encouragement (as well as financial support) for the research team."
It went on to say: "Mrs Kahlbetzer will be very fondly remembered as a great Garvan friend whose encouragement of Garvan researchers was truly remarkable."
A spokeswoman for the Institute declined to comment while the case is before the court.
Mr Kahlbetzer did not return requests for comment. He is currently the general manager of Colly Cotton Marketing and Operations Director of Twynam Agricultural Group.
The matter returns to the court's family provisions list on May 29.
