Allegations that two Great Barrier Reef Marine Park Authority board members have a conflict of interest aren’t true, an investigation has concluded.

Claims that two Great Barrier Reef Marine Park Authority (GBRMPA) board members have a conflict of interest are unfounded, an inquiry has found.

In October, former Townsville mayor Tony Mooney and the director-general of Premier Campbell Newman’s department Jon Grayson were linked to mining companies and corrupt former NSW Labor minister Eddie Obeid.

Federal Environment Minister Greg Hunt ordered legal expert Robert Cornall to investigate the claims.

Mr Cornall’s report, released on Monday, found the allegations were unfounded.

“Mr Mooney’s position as an employee of a coal explorer that does not mine or export coal and has no immediate plans to do so, does not amount to a material personal interest,” the report said.

“Mr Grayson, the Queensland Government’s nominee to the board, declared his personal interests to the Integrity Commissioner and the interests don’t conflict with his public duty.”

He also found that neither board members had links to the Obeid family and recommended no further action be taken.

Documents obtained by the ABC in October identified that GBRMPA had taken an increasingly weaker position on new port developments near the reef since September 2012.

The GBRMPA board has been asked to take a position on a series of massive port developments being planned along the Queensland coast, which environmentalists warn will devastate the reef.

Greenpeace said GBRMPA had taken a weaker stance because Mr Mooney and Mr Grayson had potential conflicts of interest.

Mr Grayson owns a one sixth share of Gasfields Water and Waste Services.

Eddie Obeid’s son, Eddie Obeid Jnr, sold off another sixth share in the same company in August.

Mr Mooney is an executive at Guildford Coal and received a $5000 donation from the Obeid Corporation when he ran for federal parliament in 2010.

Comment has been sought from Greenpeace.