Shock jock Ray Hadley is reportedly under investigation for a controversial radio interview from last Thursday when he asked the now treasurer, Scott Morrison, to swear he was telling the truth by placing his hand on a Bible.

Hadley was interviewing Morrison on the Abbott-Turnbull spill from last Monday week. Morrison was in Macquarie Radio’s Canberra studio while Hadley was in the 2UE studios in Sydney. Morrison took umbrage at the jibe and the interview soon turned heated as to why Hadley would be bringing his interviewee’s faith into it.

However, there are now claims, being reported by Fairfax Media, that it is unlawful “to administer or cause or allow to be received by any oath” unless they have been given the power to do so under an Act of Parliament. The maximum penalty if found guilty is up to two years in prison

Hadley – typically a supporter of the Liberals and open supporter of Abbott – grilled Morrison on his role in the former PM’s downfall suggesting he was lying about being offered the treasurer’s job by Malcolm Turnbull a week prior to the leadership challenge.

The then social security minister has gone on record to say he voted for Abbott during the spill, but has been accused of not doing enough to save him because he knew the result was inevitable. Hadley suggested the “deal was done” before the vote and claimed Morrison was a man of influence within the Liberal Party and should have done more to save Abbott.