A Parti Amanah Negara (Amanah) lawmaker has questioned why the Inland Revenue Board (IRB) is not probing Prime Minister Najib Abdul Razak's stepson Riza Aziz as well as Youth and Sports Minister Khairy Jamaluddin.

Kuala Terengganu MP Raja Kamarul Bahrin Shah Raja Ahmad raised this issue in the wake of IRB raiding companies belonging to Dr Mahathir Mohamad's sons.

"Riza is really young to have such wealth, compared to other veteran businesspersons who have been in the corporate world a long time," said Raja Kamarul Bahrin...