A Sydney lawyer who used part of the $6 million he misappropriated from two clients’ estates to purchase a multimillion-dollar Bondi Junction home and lease a luxury car has been struck off the roll.
Mark Leo O’Brien, formerly a partner of Harrington, Maguire & O’Brien, was struck off the roll for the misappropriation of almost $6,200,000 from two estates, which he used to discharge a mortgage, purchase a home, lease a BMW, and give cash gifts to his children.
In 2021, O’Brien was sentenced to 10 years behind bars, with a six-year non-parole period, after he pleaded guilty to dishonestly obtaining a financial advantage and knowingly dealing with proceeds of crime.
Justices Julie Ward, Kristina Stern and Stephen Free said it was clear O’Brien was not a fit and proper person to remain on the roll.
“He engaged in egregious abuse of trust in his capacity as a solicitor. The conduct was calculated and repeated over a sustained period over many years. The sums involved were substantial.
“The conduct reveals an absence of the basic qualities of honesty, trustworthiness and integrity which are required of a solicitor, and which are fundamental to the maintenance of public confidence in the profession,” the bench said in a decision made on the papers.
The Law Society was alerted to the misappropriations by a colleague of O’Brien who noticed irregularities in the firm’s trust account. The same day, O’Brien went to the Law Society’s offices and reported the conduct.
At first, the Law Society was told of the misappropriation of $1,700,000 from an estate O’Brien had been appointed executor of. The funds were meant to be for St Vincent’s Hospital and St Vincent de Paul Society.
O’Brien later admitted he misappropriated an additional $2,700,000 from the same estate and deposited it into a joint account with his wife.
While O’Brien said it was the extent of his misappropriation, the Law Society eventually discovered he had also abused his position of trust under an enduring power of attorney by transferring a total of $100,000 from the same client’s account to the joint account.
About a week after his first disclosure, O’Brien admitted he also misappropriated a total of $1,200,000 from another estate, including $200,000 meant to be split equally between the Central Sydney Area Health District and the St Vincent de Paul Society.
A further amount of almost $650,000 had been left for the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) and the Paraplegic and Quadriplegic Association of NSW (Paraquad).
O’Brien tried to cover up the misappropriation by making false entries in the trust ledger and forging documents, including a donation receipt.
The case: The Council of the Law Society of New South Wales v O’Brien [2025] NSWCA 215.
Naomi Neilson is a senior journalist with a focus on court reporting for Lawyers Weekly.
You can email Naomi at:
