The Heydon royal commission’s genesis was a favour by Julia Gillard to a boyfriend in 1992.

Two Australian Workers Union figures, Bruce Wilson and Ralph Blewitt, ran into technical issues with paperwork to incorporate an organisation called the AWU Workplace Reform Association.

Wilson called in a favour from Gillard, his girlfriend and an industrial lawyer with Slater & Gordon in Melbourne.

Gillard, who has strenuously denied any wrongdoing, sent paperwork to the Corporate Affairs Commission of Western Australia in relation to the constitution, objects and purposes of the Association.

The WA commissioner asked Gillard whether it was a “trade union”, which would have made it ineligible for incorporation, and she replied it was an association set up to “achieve safe workplaces”.

Then opposition leader Tony Abbott alleged in parliament in 2012 that Gillard made misleading statements to the commission.

Abbott said it was obvious the association was a “union slush fund”, which Wilson and Blewitt put to a range of personal uses, including possibly funding renovations at a house owned by Gillard.

Accusing her of “unethical conduct and possibly unlawful behaviour”, Abbott said a coalition government would set up a judicial inquiry specifically into the matter.

The former prime minister says she had no involvement in the association beyond giving Blewitt and Wilson “low-level” legal advice.

She had no knowledge of or any connection to its accounts and is adamant that she alone paid for her house renovations.

The association’s establishment was never a secret because its registration was advertised for public comment in a newspaper in March 1992.

Wilson told ABC TV’s 7.30 program in late 2012 he did not benefit personally from any money in the association’s account, comprised mainly of donations from building companies to support its workplace safety mandate.

Wilson said Blewitt was the only signatory to the account, had withdrawn money and, astonishingly, had buried packages of cash in his Melbourne backyard.

In a separate interview, Blewitt said he did not benefit and claimed Wilson was the “mastermind of the slush fund”, requesting cash withdrawals often in amounts of $5000 at a time.

Blewitt has given a statement to Victorian police and requested immunity from prosecution.

To date, no charges or court action have resulted from the claims.