Ex-Health Services Union boss Kathy Jackson has admitted stealing nearly $70,000 from her former employer, following previous unpublished convictions for similar fraud offences.
The former union heavyweight pleaded guilty in Victoria's County Court on Monday to two charges of obtaining financial advantage by deception.
Court documents show she misused her job to evade $67,792.85 in personal credit card debts between July 2003 and November 2010.
Jackson claimed the transactions, including for personal items and travel, as union-related expenses.
Her guilty plea means it can be revealed she was last year found guilty by a jury and convicted of two other charges of obtaining financial advantage by deception.
Jackson transferred $22,000 in union funds in 2008 to buy a Mercedes Benz from the husband of the union's former legal advisor.
She also claimed $13,100 for travel reimbursements from the union for travel and accommodation in the United States.
The same jury acquitted her of 18 theft charges, and one each of obtaining financial advantage and property by deception.
Jackson was the union's national national secretary from 2008 to 2015.
She was lauded for blowing the whistle on her predecessor, former Labor MP Craig Thomson, and former HSU general secretary Michael Williamson in 2011.
Williamson was later jailed for leeching almost $1 million from the union and recruiting others to hinder a police investigation.
Thomson was fined $25,000 following his conviction for 13 counts of theft.
After Jackson's own fall from grace, she declared bankruptcy.
The Federal Court ruled she owed the union $2.4 million, including for funds misappropriated for groceries, travel, entertainment and even her divorce.