The Dark Side of a Brilliant Barrister: Uncovering Mark Dennis's Secrets

Warning: This article contains references to child sexual abuse and suicide.

There is a small terrace house in Sydney's inner west that always gave builder Chad Loxsom an uneasy feeling.

"I've been in thousands and thousands of people's houses," he said, but this one "was a little bit strange".

The Leichhardt property belonged to Mark Dennis SC, a criminal defence barrister, who Loxsom said had a "weird demeanour" and was "just odd".

But what he saw inside is what gnawed at him for years.

"All over the walls of his house, he had dozens upon dozens upon dozens of pictures of him with little kids," he said.

In some photos, Loxsom said Dennis was hugging shirtless children.

Loxsom shared his suspicions with an electrician.

"His gut was this guy was doing something bad with kids as well," he said.

The electrician first noticed the "come back with a warrant" doormat, and then the large mirror fixed to the ceiling above Dennis's bed.

But, like Loxsom, what really alarmed him was the sheer volume of photographs in almost every room, even the kitchen.

"It was just disturbing. Like, these kids weren't happy," he said.

Dennis was found dead in his home in Sydney's inner west in February.

Eventually, Loxsom decided to make a report with the child protection hotline.

"I didn't do it straight away, which now I regret," he said.

In January, Dennis came onto the police's radar again when he was searched at Sydney Airport as he returned from a trip to Cambodia.

What was found on his devices led to his arrest, a raid of his house, and child abuse material charges from evidence prosecutors described as "disturbing".

Dennis was released on bail, and soon after, was found dead in his home.

Last week, it was revealed his death did not bring the police investigation to an end.

Codenamed Operation Queenstown, national police have been quietly probing Dennis's network and links to famous children's charity Sunrise Cambodia all year.

The investigation can reveal allegations that Dennis sexually harassed a former Sunrise staff member and made teenage girls feel uncomfortable by excessive touching.

The claims raise important questions for all children's charities that must balance the need to fundraise with child safety, as multiple former Sunrise staff say they saw Dennis's bad behaviour but felt they could not report it.

"They saw this," one former staff member told investigators through a translator. "But they could not do anything because he's a big sponsor."

A spokesperson for Sunrise said they were never aware of any complaints about Dennis and police had told them no current or former Sunrise child had been identified as one of his victims.

The charity defended its child protection policies, saying the children always came first.

'Married to the profession'

Dennis grew up in a large family on Sydney's northern beaches, and by 2001, was a criminal defence barrister with a room at the prestigious Forbes Chambers.

"You don't get to go to Forbes unless you are absolutely brilliant," says one solicitor who briefed Dennis.

"He was one of those people who was married to the profession."

His nickname was "Dark Menace" — a play on words that several acquaintances said reflected his personality and black sense of humour, exemplified by his "WASNTME" personalised number plate.

Across his career, Dennis was known to have mentored junior lawyers and published papers under provocative titles and on topics like defending accused paedophiles and cross-examining child witnesses.

Some of the legal papers authored by Dennis.

"You need to watch the child witness carefully and assess matters such as intelligence, level of vocabulary and articulation, degree of self-confidence, general demeanour," he wrote in 2017.

One lawyer who knew Dennis for more than a decade said he was "not shocked" by the charges because he had a reputation for sexual harassment and aggression towards women.

"It's one of those situations where, and I know I'm not the only person who's thought about this, I think a lot of us in retrospect are like, 'This was actually f***ing obvious,'" he said.

Three lawyers told investigators about an incident where Dennis was intoxicated at the 2012 Aboriginal Legal Service (ALS) Christmas party in Sydney, when he lunged at a woman with an open fist.

He was then banned from ALS Christmas parties.

Barrister Charles Waterstreet, who worked at Forbes alongside Dennis for more than a decade until facing his own sexual misconduct allegations, described his former colleague as "very ambitious" but "an oddball".

"He loved a drink, especially on Friday nights," he said. "He sort of became another personality."

Forbes Chambers is on the 11th floor of a building overlooking Sydney's Hyde Park.

In 2011, Dennis began hosting legal conferences to raise funds for his charity, Reasonable Cause, that pledged to help "disadvantaged young Cambodians to further their education".

Tickets cost $450, and the guest list included magistrates, silks and politicians, according to the 2024 invitation.

In interviews with more than 20 sitting Forbes barristers, some were quick to defend their late colleague — insinuating the evidence was thin, based on industry rumours, and one said they did not think his charity work should be "smeared".

"It did such good work. I don't think it was connected … to some sexual interest," they said.

However, despite some celebrating his work and attending his legal conferences, many could not name the charity the money went to.

From sponsor to chairman

The largest recipient of Dennis's fundraising was Sunrise Cambodia — a high-profile children's charity founded by Adelaide-born Geraldine Cox.

Cox has spent decades crisscrossing the globe, and according to her 2011 report, delivering speeches to company executives in the United Arab Emirates, government officials in Australia, private schools, and lawyers like Dennis.

"I flew to Sydney to address a group of lawyers at an event arranged by sponsor Mark Dennis, where over $14,000 was raised. Who said lawyers do not have hearts!" Cox wrote.

Her work has been celebrated internationally.

She has won awards, been praised by media and rubbed shoulders with Hollywood celebrities and Australian prime ministers.

Geraldine Cox's work has brought her into contact with the likes of Angelina Jolie, Brad Pitt and Anthony Albanese.

Starting in 2008, Dennis personally sponsored a handful of children at Sunrise whom he visited in the orphanages each year.

Over time, he backed the whole organisation — raising at least $340,000 in seven years through the legal conferences.

In 2010, he also began funding and attending Sunrise's annual beach holidays to Sihanoukville, a once-sleepy Cambodian coastal town now filled with scam compounds and casinos.

Itineraries for these trips obtained show the children played football, shared meals, performed concerts and socialised with sponsors, including Dennis.

Photographs from these trips show Dennis on the beach, and hugging and playing with young children at the hotel.

There is no suggestion the photographs are sexual.

Dennis playing with children during one of the Sunrise trips to Sihanoukville.

A spokesperson for Sunrise said sponsors were not permitted to initiate contact with children.

"However, if a child comes running at a sponsor for a hug, the sponsor is not expected to push them away as this can be very emotionally damaging to a kid who may actually feel safe for the first time in his/her life," they said.

A former Sunrise employee told investigators it was during one of these beach trips that Dennis's behaviour was concerning.