Just when you thought you heard enough about the Irwin's...

BOB Irwin will tell his version of the Irwin family rift to the ABC's Australian Story on Monday, as his daughter-in-law, Terri, deals with an investigation into Australia Zoo's tax arrangements.

The ABC said yesterday it had secured the patriarch's story, the same day as the zoo was grappling with the fallout from an investigation into an offshore tax scheme.

Australia Zoo's general manager, Frank Muscillo, married to Mr Irwin's daughter, confirmed that the Australian Tax Office was looking into its tax arrangements.

The zoo contacted the Tax Office last year after discovering problems with a tax scheme promoted by a Singapore company, which used a former assistant tax commissioner, Nick Petroulias, as a consultant.

This led to a $2.5 million lawsuit against the Sunshine Coast zoo and its owner, Terri Irwin, widow of Steve, in the Victorian County Court, with a ruling on its legitimacy expected from the Tax Office.

Mr Muscillo said the zoo thought the scheme legitimate when it signed on, but now claims it was one of hundreds of victims of a sophisticated deception.

"We would certainly never knowingly have become involved or associated ourselves with anything illegal or deceitful," he said.

The Australian Securities and Investments Commission and the Commonwealth Director of Public Prosecutions were also involved, but Mr Muscillo did not provide details.

He was confident the zoo would win the civil lawsuit, set down for a 15-day hearing in Melbourne in October, but acknowledged the damage inflicted by the tax investigation.

The matter is unlikely to be helped by the Bob Iwin interview. The ABC filmed it on Iron Bark Station, the zoo's wildlife sanctuary, which Mr Irwin will soon quit for a nearby property of his own, on which he has vowed to continue the conservation dream of his son, Steve.

The interview was filmed about the same time as Terri Irwin denied any family rift to reporters, and professed her love for Mr Irwin.