“I have enjoyed such a close, trusting relationship with Andrew for the past four years, and that will continue,” Forrest said.

Hagger said he would work closely with Hartman and the directors to ensure a smooth transition.

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“Minderoo and Tattarang are in such strong positions, so it’s a good time to turn my attention to other things in life,” Hagger said.

Previously Hagger was NAB chief customer officer for consumer banking and was accused of “not being candid” with the corporate watchdog the Australian Securities and Investments Commission at a torrid hearing of the Hayne banking royal commission.

Hartman, 36, has advised Forrest on investments for a decade during which the value of the portfolio under his control has soared.

To now head Tattarang - Australia’s largest private investment group - is an extraordinary achievement given the former Sydney-based stockbroker’s predicament before Forrest employed him.

In December 2010 Hartman was sentenced to 4½ years’ jail (later reduced to 15 months on appeal) for giving a school friend insider information in exchange for an even split of the profits.

Hartman pleaded guilty to 19 charges of insider trading and agreed to testify against school friend Oliver Curtis.

It was not until Hartman was free and working for Forrest in 2016 that he was called to be a witness in a case where his fellow Saint Ignatius College Riverview alumni was sentenced to a minimum of one year in jail.

Hartman said it had been a privilege to work with Hagger.

“We have worked together overseeing a period of strong growth and diversification for Tattarang, and I’m proud to have been part of the strong Minderoo Foundation leadership team that Andrew Hagger helped form,” he said.

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