She said that after WWII the United States army and Australian defence forces dumped sizeable amounts of dangerous material off Townsville and other Australian cities.

"Over 1000 mustard-charged bombs were sunk at two sites about 200km northeast of Townsville in October 1945 and extensive dumping of other bombs, artillery shells and gas containers is also thought to have occurred," Ms Nelson-Carr said.

"Expert advice is that the mustard gas now poses no threat and it's unlikely that the public would come into contact, although these days trawlers work in depths where dumped material could accidentally be recovered.

"Some bomb sites have been documented, however a comprehensive record of all locations and the full range of explosives have not been made public, if in fact a complete list is even known."

Ms Nelson-Carr, who is also Parliamentary Secretary to the Premier in North Queensland, said media reports had pointed to poor and fragmented record-keeping which had hindered investigations into the whereabouts of chemical weapons.

Federal Member for Herbert Peter Lindsay said the Department of Defence maintained a record of sites confirmed as or suspected of being contaminated with unexploded ordnance, or UXO.

He said there were over 400 sites in Queensland where, because of military activity mainly during World War II, there are or could be items of UXO remaining. They stretched from Torres Strait to the NSW border and as far west as Cloncurry.

Information on the whereabouts of any dangerous materials off Townsville was still being sought.

Ms Nelson-Carr said even if post-WWII bomb dumping posed little or no threat, the public had a right to be reminded that the dumps existed.

"The US military during the war is said to have had chemical weapons storage sites at Charters Towers and at a place just north of Townsville," she said.