The stood-aside Queensland Transport and Main Roads director-general, Michael Caltabiano, has been sacked in a tumultuous day in state politics.

He had been under fire over a job given to a minister's son and comments about their prior work history.

Queensland's Crime and Misconduct Commission (CMC) is investigating the appointment of former arts minister Ros Bates' son, Ben Gommers, to a job in the Transport Department.

Mr Caltabiano is also being investigated over claims he misled a budget estimates hearing about his work history with Mr Gommers.

He stood aside from his position last October while the CMC investigated the claims.

But today Queensland Premier Campbell Newman released a statement saying Mr Caltabiano's employment would be terminated on March 15.

The Premier added however the bureaucrat would remain on leave until then.

News of his sacking came after from the Cabinet, citing health reasons.

Mr Newman is yet to announce a replacement for Ms Bates and is considering a wider Cabinet reshuffle.