The Queensland Government appointed an Adani company director to chair the authority overseeing the Abbot Point coal port, despite being warned of "potential conflicts of interest".

Key points: "It's undoubtedly a conflict of interest," said law professor on Mr Fish's appointment

"It's undoubtedly a conflict of interest," said law professor on Mr Fish's appointment Treasurer's office confirms it knew of Mr Fish's directorship and that he "disclosed potential conflicts of interest prior to his appointment"

Treasurer's office confirms it knew of Mr Fish's directorship and that he "disclosed potential conflicts of interest prior to his appointment" But Mr Fish's link to Adani was not disclosed publicly by the Treasurer when he was appointed

Brad Fish was a director of Adani's Abbot Point Operations Pty Ltd when he was made the chair of the state-owned North Queensland Bulk Ports Corporation (NQBP).

NQBP oversees the ports at Weipa, Mackay, Hay Point and Abbot Point.

Adani runs the only operating coal terminal at Abbot Point, north of Bowen.

Mr Fish's appointment as NQBP chair was made in September 2015 by Treasurer Curtis Pitt.

He did not resign the directorship of Abbot Point Operations until November 11, 2015.

"It's undoubtedly a conflict of interest, and the real question then becomes how do you manage the conflict," said University of Queensland Professor of Commercial Law, Ross Grantham.

Nik Casule from Greenpeace Australia Pacific said the appointment raised serious questions.

"Mr Fish was chairman of North Queensland Bulk Ports that was responsible for regulating the port of Abbot Point at the same time as he was director of a company that was profiting from the operations of that port," Mr Casule said.

The Treasurer's office has confirmed to the ABC that it knew of Mr Fish's directorship and that he "disclosed potential conflicts of interest prior to his appointment".

But Mr Fish's directorship with Abbot Point Operations was not disclosed publicly by Mr Pitt's office or North Queensland Bulk Ports Corporation at the time of his appointment.

The ABC approached Mr Fish through NQBP.

Got a confidential news tip? Email ABC Investigations at investigations@abc.net.au For more sensitive information: Text message using the Signal phone app +61 436 369 072 No system is 100 per cent secure, but the Signal app uses end-to-end encryption and can protect your identity. Please read the terms and conditions.

In a statement, NQBP said: "Mr Fish continues to be precluded from considering, being involved in discussions or receiving documents relating to commercial decisions regarding Adani."

"The requirement for Mr Fish to be precluded from relevant sections of Board or Committee meetings has been an infrequent occurrence," an NQBP spokesman said.

"However the requirements under the protocol are strictly enforced where applicable."

"If the person concerned is not able to be involved in discussions between the port authority and the client then you wonder whether the person is really able to fully discharge their duties," said Professor Grantham.

Sorry, this video has expired Adani's complex corporate web

Mr Fish has a long history with North Queensland Bulk Ports.

Before becoming a director of Abbot Point Operations he was the CEO of NQBP for 14 years.

The ABC asked the Treasurer's office why the Government did not publicly disclose the "potential conflict of interest" involving Mr Fish.

It failed to respond.

"[As] the shareholding minister, the Treasurer has a responsibility as the effective owner of the authority to be accountable to the public," said Professor Grantham.