The Federal Government has stepped in after it was revealed the Royal Flying Doctor Service (RFDS) has been in breach of the federal Crimes Act for the past 20 years.

The organisation was unaware it was illegal to distribute high-grade painkillers such as morphine and pethidine via Australia Post.

The Government will make changes to the Act to allow the service to re-stock its remote medicine chests.

The Federal Minister for Rural and Regional Health, Warren Snowdon, said it was imperative the Government acted swiftly to ensure people would be looked after in medical emergencies.

"We needed to get a change to the Crimes Act effectively to make it OK for Australia Post to handle these sorts of drugs on behalf of the RFDS," he said.

"We were able to work with the Minister for Justice, Brendan O'Connor, and get an amendment made to the Act to allow this to happen."