An American ship disposal expert is disputing a claim by Australia's Minister of Planning, Tony Kelly, that paint in the HMAS Adelaide has no toxic lead.
Werner Hoyt, also a naval engineer, submitted samples of toxic paint from the Adelaide to the Administrative Appeals Tribunal as evidence.
An estimated 11 tonnes of paint with lead cover the ship's exterior and interior.
Peter deFur, a toxicologist who also gave evidence to the tribunal, said the lead in the paint can mix with water and contaminate fish eaten by people.
Samples of the paint will be tested and the result will be presented in the hearing of the case on July 16.
In March, Kelly described the boat as the first environmental ship.
The Adelaide was supposed to be sunk on July 9 but lobbyists prevented the sinking.