The Australian government is seeking at least $120 million from the owners of a Chinese coal carrier that destroyed part of the Great Barrier Reef.
Shenzhen Energy Transport is fighting not to pay for the clean-up of the Douglas Shoal, which was severely damaged when the Shen Neng 1 went off course and grounded in April 2010.
The Federal Court heard on Tuesday that the crash site is contaminated with hundreds of kilograms of paint particles tainted with the highly-toxic anti-fouling agent tributyltin, also known as TBT.
TBT slows the growth of aquatic organisms on ship hulls and marine biologists say the particles need to be removed from the 40ha crash site to allow the area to recover.
But the carrier's owner claims the reef is self-healing and the company should not have to pay for a clean-up that is not needed.
It also disputes the testing methods that led to the detection of TBT in the area.
Shenzhen Energy Transport's maritime insurer, London P&I Club, said in a statement the Australian government's estimated costs of fixing the reef were "unsubstantiated and unrealistic".
In 2012, captain Jichang Wang and chief officer-on-watch Xuegang Wang were convicted over their role in the negligent navigation that led to the grounding.
Both men were employed by an independent ship management company.
The hearing continues.
