Treasurer Jim Chalmers has labelled reports the Medicare system is being rorted by up to $8 billion a year as atrocious.

The comments come after a joint ABC and Nine newspapers investigation revealed some practitioners were ripping off the system and charging for services that were never delivered.

According to the report, some doctors have been billing dead people and falsifying patient medical records to lift their incomes. Others were making mistakes on claims.

Dr Chalmers said the government was investigating the allegations.

"If these numbers are true, it's absolutely atrocious. Every dollar rorted, whether it's from Medicare or the NDIS, is a dollar thieved from people who need and deserve good health care," he told reporters in Canberra on Monday.

"If you're stealing from Medicare or the NDIS, you're a grub. It means that money that's not exactly thick on the ground in the budget is not going to people who need it."

Dr Chalmers wants a crackdown on people who rort the Medicare system, describing the report as very troubling.

"(It is) something that we will get to the bottom of because we don't want to see a single dollar rorted or thieved from the system when it could go to helping people who are vulnerable," he said.

Government Services Minister Bill Shorten said while the "vast majority" of general practitioners did the right thing, payment integrity was a problem.

"It drives taxpayers to despair if they think that some people are opportunistically rorting the system," he told Nine's Today show on Monday.

"Crooks do leave footprints ... obviously we have got to make sure there is complete confidence in the system but we need to put the crooks on notice that 'you will get caught'."

Environment Minister Tanya Plibersek, a former health minister, told Seven's Sunrise program the report was shocking.

"We need to come down on these people like a tonne of bricks because Australians feel protective of Medicare and they want to keep Medicare and they love the way our health system works, but it cannot work if you have people ripping it off," she said.