The fight is back on in a dispute that could shake up the traditional real estate industry. The battle boils down to whether real estate brokers can give the public unfettered online access to important home sales information.

This week, Canada's Competition Bureau is back before the federal Competition Tribunal in Toronto, continuing its ongoing lawsuit against the Toronto Real Estate Board (TREB) in a test case that could affect other regions.

The bureau wants to remove TREB's power to keep under lock and key crucial house hunting information such as previous home listings, the length of time a house is on the market and "sold" data — the price homes have sold for in the market.

"TREB's anti-competitive behaviour continues to restrict potential home buyers and sellers from taking advantage of a greater range of service and pricing options when making one of the most significant financial transactions of their lives," said the Competition Bureau in a statement to CBC News.

The battle over sold data

At the heart of the matter is whether recent sold data should be made accessible to the public without being relayed through a real estate agent. The information can empower homebuyers and sellers by helping them gauge a property's value by comparing it to current home sales.

"The sold data is the most important thing," says real estate broker Ara Mamourian. "It's what people usually ask us for."

TREB gives agents access to recent sold stats and other details that they can offer to personal clients. Yet Canada's largest real estate board maintains that agents cannot publicly post the data online because of privacy issues.

"The Toronto Real Estate Board will continue to work to protect the personal information entrusted to it," TREB CEO John DiMichele told CBC News in an email.

Mamourian, who runs Spring Realty in Toronto, argues that in the age of the internet, consumers should be able to freely access sold stats when house hunting online.

"People are making huge financial decisions based on those [sold] prices. So why not put it out there?"

Putting sold stats out there

Already in Nova Scotia, and for years across the U.S., realty websites publicly post home sales history.

Some Toronto brokers, including Mamourian, also recently decided to give people easy access online. They skirted TREB's rules by making the data available to registered users instead of posting it for everyone to view.

TREB then sent a stern warning letter to brokers in February. It threatened that anyone defying its rules would be "suspended or terminated immediately" from the Multiple Listing Service (MLS) — an important database for agents. A few real estate agencies balked and quickly shut down their sold data services.

But Mamourian pledged to continue emailing the information to registered customers.

"It's 2015, not 1980 any more. The way people expect to receive information has changed, and we're just simply giving people what they want," he told CBC in March.

Waiting for the green light

'I know that TREB's going to fight it pretty damn hard.' - Ara Mamourian, broker, Spring Realty

But now, the broker has halted his sold data mailouts and has decided to wait for the outcome of the Federal Competition Tribunal.

"We did a risk reward analysis on this whole thing and looked at the worst-case scenario which is having TREB coming down on us with some kind of fines or whatever they do and the time it would take to defend something like that," Mamourian explains.

He says considering how much time it takes him to compile sold stats and the fact his clients found weekly emails weren't overly useful, he concluded the risk wasn't worth it.

But he says if the Competition Bureau wins its case, he will publicly offer sold details on Spring Realty's real estate search site. "The day that we're actually allowed to display this data on our website, we're going to integrate it into our search tool."

Mamourian is optimistic that day will come. He points to other industries like travel where the internet has allowed consumers to bypass travel agents to access information to book trips.

"I know that TREB's going to fight it pretty damn hard. But I think that this time around there might be a little bit of a tipping point with the way technology is and the way consumers are already receiving information in other industries."

Anticipating victory

Other brokers are also watching the case carefully. 

Broker Fraser Beach is still emailing recent sold prices to people who sign up for his service. But the owner of Select/Plan Real Estate says he does so at his own risk.

"It's an ongoing concern because the bottom line is TREB could pull the plug based on their assertion that I was doing something wrong. And then it is a very arduous procedure to combat that."

Beach would know. TREB axed his access to MLS in 2007 after he launched a website that offered broad access to real estate data including sold price information. He then unsuccessfully sued TREB.

But the broker is also hopeful that the Competition Bureau will be triumphant. In fact, he recently fine-tuned his sold data service with a new website in anticipation of a victory.

"Technology changes things and this is an evolution of the way the business should be conducted," he said.