The timber industry says up to 2000 jobs are under threat because of a decision to use concrete sleepers to upgrade the Melbourne to Brisbane rail line.

Hundreds of timber sleepers have been stolen from Melbourne's rail network and used as firewood, despite concerns they contain traces of asbestos. Danger warning on stolen rail sleepers.

The timber cutters say QR will not renew local contracts for the supply of railway sleepers and is moving to a tender process next month. Sleeper supplier Peter Fields says the change will cost jobs.