Two journalist data warrants issued

West Australian police have twice been allowed to access a journalist's communications data over possible criminal offences.

The Attorney-General's Department, in a report tabled on Monday, said two journalist information warrants were issued from October 2015 to June 2016.

A total of 33 authorisations were made under the warrants, which allow enforcement agencies to disclose metadata to identify a journalist's source.

"These authorisations were for the purpose of enforcing the criminal law," the 2015-16 annual report into the Telecommunications (Interception and Access) Act said.

The warrants were part of the federal government's sweeping data retention laws introduced in 2015.

The report noted that the data retention scheme, which requires the metadata of every Australian's mobile and online communications to be collected and stored for two years, has cost the industry nearly $200 million to implement.

A majority of that, $128 million, has been covered by taxpayers through grants.