PUTRAJAYA: The Inland Revenue Board (IRB) can now resume its bankruptcy notice hearing against incarcerated former prime minister Datuk Seri Najib Razak and his son Datuk Nazifuddin to recoup billions of ringgit in unpaid tax from the duo.

A source from the Attorney-General's Chambers (AGC) said the duo had exhausted their final avenue to overturn the High Court's decision compelling them to settle RM1.69 billion and RM37.6 million in unpaid taxes and penalties respectively.