UPDATE 30/08 - Asbestos has been found on another Australian work site.

ORIGINAL - More asbestos-tainted products have turned up on an Australian worksite.

Asbestos was found in equipment for Port Pirie's Nyrstar $563-million smelter redevelopment, sourced from China.

SafeWork SA is investigating, and has prohibited all work in the vicinity of the asbestos in the acid plant section of the project.

Workers discovered asbestos in eight contaminated heat exchanger tubes, each about 20 metres long, that are used to dissipate heat during the production process.

The Australian Workers Union (AWU) says it appears that protective equipment minimised any exposure.

The union has called for a high-level inquiry into how materials keep turning up in Australia.

It says the pieces of equipment involved are enormous, and so would be easy to check.

The South Australian Government wants an urgent meeting with the Federal Government to talk about Australian Border Force's failures to detect asbestos-tainted imports.