Fairfax Media can reveal that the man once known as Senator for Kneecaps is a "person of interest" to the anti-corruption body.

In recent weeks ICAC investigators have been taking statements over a particular property deal in which Mr Richardson was engaged as a lobbyist.

It is understood that the planned public hearing into allegations of corruption involving former independent State MP Richard Torbay has been delayed due to the new avenues of inquiry.

In a separate development, the NSW state branch of the ALP has handed to ICAC a vast amount of emails covering the period 2004 to 2010.

Fairfax Media has been told that the two inquiries have some common features, including a link to Robert Fiszman, whose late father Sam was one described in the NSW Parliament as "a bagman for the Labor Party".

Mr Torbay, 53, was sensationally referred to the ICAC and dumped as a federal National Party candidate in March 2013.

Part of the long-running investigation into Mr Torbay involves allegations that the then Armidale-based MP was being secretly bankrolled by the Labor Party from funds obtained from developer donations.

Mr Torbay is alleged to have received a suitcase containing $50,000 in cash provided by corrupt former powerbroker Eddie Obeid, a claim which Mr Obeid has denied.

As general secretary of the NSW ALP branch in the late 1970s, Mr Richardson's legendary skills as a political bagman were honed. His prodigious ability to extract donations from developers and entrepreneurs continued throughout his years as senator.

A series of scandals saw him retire from federal politics in 1994. He worked for a number of years for the late media tycoon Kerry Packer. In recent years he has worked as a lobbyist for a string of developers. Fairfax Media does not suggest any wrongdoing on behalf of Mr Richardson's clients.

With regard to his lobbying activities, Mr Richardson has previously told Fairfax Media that he didn't need to lobby planning ministers: "I don't have to talk to ministers; I can get things done through other means… I have known people in the bureaucracy for years. I have lots of contacts, lots of ways to press for things."

Mr Richardson is presently listed on the lobbyist register as having one client, property developer Lang Walker's company Walker Corporation. According to Australian Electoral Commission records, since 1998 Walker Corp has donated $2,253,480 to political parties, mostly to the ALP.

The former powerbroker suffered a financial setback after a prolonged legal battle with the Australian Tax Office over a $2.3 million tax assessment from profits in a Swiss bank account.

Mr Richardson claimed that the funds in the Swiss accounts were a gift from his close friend, the late disgraced stockbroker Rene Rivkin.

He reached a confidential settlement with the ATO in 2010. A few weeks later it was revealed that in 1994 Mr Richardson had sent $1 million from his Swiss account to a bank in Beirut. The Beirut account was operated by a close associate of Mr Richardson's friend Eddie Obeid. Mr Richardson told the authors of He Who Must Be Obeid that he didn't recall the transaction but if he did transfer the money, "It was under the instructions of Rivkin".

In July this year Mr Richardson and his friend Danny Meares, of Danny's Seafood fame, bought the Watermark Restaurant on The Strand in Townsville for $3.6 million.

Mr Richardson, who introduced Mr Meares to the deal, owns 10 per cent of the purchasing company, Farnorth Properties.

In September Mr Richardson, who works as a political commentator for News Corp and Sky News, used Twitter to post a photo of himself celebrating his 65th birthday at his new restaurant with the Mayor of Townsville, Jenny Hill.

Mr Richardson did not return Fairfax Media's call.