Two of Western Australia's most senior public servants face being held in contempt of Parliament.

Darren Foster, the director general of the Department of Premier and Cabinet, has been accused of “prima facie, an extremely serious intentional breach of parliamentary privilege”.

The department's acting director general Emily Roper has also been slammed for refusing to comply with a summons issued by the Procedures and Privileges Committee to hand over thousands of emails and documents belonging to the three former MPs and their staff, as part of a Corruption and Crime Commission (CCC) investigation.

The committee's report says the CCC issued the Department of Premier and Cabinet two notices to produce over three years’ worth of emails and documents sent via the parliamentary email accounts of three former MPs and their staff.

The privileges committee had a method to deal with how the CCC could access these documents without breaching Legislative Council privileges.

However, the report says the Department of Premier and Cabinet later advised the committee that it devised its own way of identifying privileged documents “that it intended to follow in order to expedite the production of the documents to the CCC”.

Even though Mr Foster was warned he and his staff risked being in contempt of Parliament, it appears they went ahead with their own sorting process, sending only certain documents to the CCC.

The privileges committee then moved to audit the documents the department had sent to the CCC.

It issued a summons to Ms Roper, in Mr Foster's absence overseas, to produce copies of all the documents provided to the CCC.

Ms Roper allegedly refused to do so.

Legislative Council president and Labor MP Kate Doust said there had been “cavalier disregard” of the committee's right to the documents.

“These two related matters of privilege and their effect on the sources of information to the Parliament and its members strike at the heart of our democratic institutions,” she said.