THE substitution of cheap mutton and hogget for lamb is a problem that needs to be tackled with tougher enforcement, a Senate committee says in its interim report into meat marketing.

Every animal destined to become butcher shop "lamb" should have its mouth checked before slaughter to ensure the integrity of the high-priced meat, the report has recommended.

And regulations across the country covering domestic meat slaughtering and processing should be made uniform.

In Australia, lamb can come only from an animal that has not cut any adult teeth. But once the animal's head has been removed at an abattoir, telling the difference between lamb and older sheep can be difficult.

The Senate's Rural and Regional Affairs Committee heard evidence - particularly from NSW meat processors - that substitution was rife. Most blamed their Victorian counterparts.

The committee found that substitution, "while not widespread throughout Australia, is a legitimate cause of concern to the industry. The committee recognises that substitution … is difficult to prove."

The Sheepmeat Council of Australia told the inquiry of "a range of different regulatory and compliance systems across federal and state jurisdictions that underpin, to varying degrees, the practice of lamb branding.

Each federal and state authority operates under different legislation, with varying standards."

The report recommends all jurisdictions consider adopting the tough compliance and enforcement regime of Western Australia, which has jailed people for lamb fraud.

While some jurisdictions check only a percentage of mouths for adult teeth, in WA each animal is checked under the supervision of an inspector and carcasses are marked before heads are removed.

Chris Groves, the president of the Sheepmeat Council, said the harmonised system should be more than simply a copy of WA's standard.

Daniel Lewis