The Abbott government has announced an independent review of how two leaking incidents occurred in the protective wall of Gladstone Harbour.

The Australian Greens warn that an inquiry into a leaking wall designed to keep toxic material out of Gladstone Harbour could dissolve into a political witchhunt.

The federal government on Thursday announced a review into whether it was a failure of design or construction that saw the protective bund wall at the Port of Gladstone leak in 2011 and 2012.

The wall was designed to hold 25 million tonnes of dredged soil, and environment groups claim the leak caused dangerous chemicals to leach into the harbour, affecting marine life in the area.

The Greens are concerned the inquiry will focus solely on the failure of the bund wall, not the broader impact of dredging and dumping during the expansion of Gladstone port.

Greens senator Larissa Waters said limiting the scope of the review would allow the government to target former state and federal Labor governments involved in the project.

“Feigning concern for the environment to disguise political point scoring would be utterly disgraceful, although hardly surprising from the Abbott government,” she said in a statement.

The western basin dredging project at the Port of Gladstone was approved by the Gillard Labor government in October 2010.

Environment Minister Greg Hunt said it was clear there had been a failure in the wall, and it was his job to ensure the health of nearby oceans and harbours.

“It is the responsibility of a new government to investigate what went wrong and why and to make sure it does not happen again,” Mr Hunt said.

It comes as the Great Barrier Reef Marine Park Authority considers allowing for 3 million cubic metres of dredged seabed from Queensland’s Abbot Point development to be dumped offshore.

Senator Waters said given the “disaster” during the Gladstone Harbour expansion, it was crucial the authority refuse to allow for further dredging and dumping.

The Greens have threatened to call for a Senate inquiry into the leak if the review called by Mr Hunt is not given adequate investigative powers.

The review findings will be finalised by the end of March.