Despite the Elizabeth Bay penthouse golf putting green, David Gonski could yet play neighbourhood tennis

Harbourside rooftop penthouse golf putting doesn't quite fit the reputed buyer's Who's Who leisure profile.

But the unconfirmed purchaser of the recently settled prestigious Elizabeth Bay penthouse offering is tipped as the bookish David Gonski, the consummate Sydney business networker and chairman of the Future Fund.

He's been in the headlines of late given his report of schools funding for the Gillard government.

He is chairman of Investec Australia, the bank that bought his corporate advisory firm, Wentworth Associates, in 2001.

The Billyard Avenue apartment sale through Savills agent Martin Schiller has been officially registered at $12 million but to a holding company fronted by a non-beneficial director, the solicitor and corporate finance adviser, Mark Cohen, who since 2010 has been an Investec director. That's among the best links that assist Title Tattle in the identification of the mystery buyer. The SMH's Margie Blok gave it her best shot last weekend but stopped a bit short of the pin when she speculatively queried: "Which extremely high-profile businessman and philanthropist seems to be the mystery buyer of a lavish eastern suburbs penthouse bought in the name of a nominee company?"

The apartment last traded at $14 million in 2006 when bought by Hal Herron, the former Deutsche banker. The penthouse is atop the lavish Burley Katon Halliday complex of six apartments built in 1998 on the site of Cardigan, the former home of the late Cedric and Elizabeth Symonds, by the East Asia Property group. Totalling 425 square metres internally, it has vast living area and a 375-square-metre terrace with harbour views. Herron had bought the penthouse from ballet clothing manufacturer David Wilkenfeld, who paid $7.1 million for it in 2001.

Gonski hasn't given any indication of departing Point Piper, given the apartment has actually been listed for rent at about $5,000 a week through Ballard Property Group.

The Ballard Proeprty Group website says it now has a tenancy deposit taken.

The penthouse apartment comes with a three pin rooftop putting green. Title Tattle notes some golfing lineage in the family as Gonski's father, Alexander, was a neurosurgeon and a founding member of the New South Wales Gold Club at La Perouse.

David Gonski certainly does play tennis, so he could always become friends with other Elizabeth Bay harbourfront owners who have  tennis courts, namely the Onisforou and Paspaley families.