Investigations into the cause of the collapse have led to conviction and imprisonment of a handful of members of HIH management on various charges relating to fraud.

The board hoped this would give HIH time to review its operations and assess its financial position.

He attributed the HIH company failures to rapid expansion, unsupervised delegation of authority, extensive and complex reinsurance arrangements, under-pricing, reserve problems, false reports, reckless management, incompetence, fraud, greed, and self-dealing.

[4][needs update] On 21 May 2001 Prime Minister John Howard announced that a Royal Commission would be established to inquire into the company's collapse.

[4] Justice Neville John Owen headed the Royal Commission, which tabled its report to Parliament on 16 April 2003.

Criminal charges for stock market manipulation were laid against Adler after an investigation by the Australian Securities & Investments Commission (ASIC) into the purchase of HIH shares by Pacific Eagle Equities Pty Ltd, an Adler-controlled company.

[6] Adler also told the journalist that he believed the share price for HIH was undervalued and presented an opportunity for a quick profit.

[8] On 13 October 2007, Adler was released from the St Heliers Correctional Centre in the Hunter Valley on parole, after serving 2+1⁄2 years of his sentence.

However, in November 2007, he faced court in a NSW civil case related to bonuses he recommended for executives of the failed telco One.Tel.

[11] Sydney businessman Brad Cooper was sentenced in the Supreme Court on 23 June 2006, after a jury found him guilty on 13 charges relating to bribes he paid a senior HIH official to push through false claims in the months before the insurer's collapse.

[13] Cooper reportedly admitted to having a cocaine addiction during his high-flying days when he worked as a motivational speaker and as a salesman.

[12] On 21 November 2008, it was reported that a charge had been dropped against former HIH chairman Geoffrey Cohen a week before it was due to be heard in Sydney's Downing Centre Local Court.

Both abandoned charges related to Cohen's address to shareholders at the HIH annual general meeting in December 2000.