TORONTO -- A lawyer for the Competition Bureau says the Toronto Real Estate Board is stifling digital innovation and lessening competition by prohibiting its realtor members from posting an array of data on their websites -- including what homes have sold for.

John Rook, a lawyer representing the bureau, says the real estate board is standing between consumers and the data because it fears competition from online startups could spark a price war and lead to lower commissions for its member real estate agents.

"They did this with malice and forethought," Rook told the competition tribunal on Tuesday.

The real estate board disputed those claims, arguing that although realtors provide data such as the final selling price of a home to their clients, that information should not be openly displayed online where it could be viewed by "anyone with an Internet connection."

"Some of that data is personal and very sensitive," Donald Affleck, a lawyer for the board, told the hearing.

Affleck said TREB's decision to prohibit its members from posting the data online was not motivated by a desire to lessen competition but rather with the privacy of buyers and sellers in mind.

The case is expected to have reverberations throughout the country, and could affect how other Canadian real estate boards provide services to their customers online.

However, a lawyer for the Canadian Real Estate Association -- which has been granted intervenor status in the case -- argued Tuesday that any decisions rendered in the case should not be applied to other real estate boards.

Sandra Forbes, the lawyer for CREA, said real estate boards in Saskatchewan or Manitoba are very different from the one in the Greater Toronto Area.

"Everyone is operating in a different competitive environment," Forbes said.

Forbes also argued that preventing easy access to certain sensitive data does not prevent realtors from operating successful websites and offering services to clients in innovative ways.

"Innovation over the Internet is not on trial here," she said.

The Competition Bureau's case against TREB was first heard back in 2011. The bureau lost but the Federal Court of Appeal later overturned the decision.

The oft-delayed case got underway Tuesday afternoon after facing another setback Monday due to a motion put forward by TREB.

The real estate board had requested Federal Court Chief Justice Paul Crampton remove himself from the hearing due to concerns that he could be perceived as being biased because of his involvement in a similar case when he was a layer more than a decade ago.

However, the three-member panel overturned the motion, stating that a reasonable person would not accuse Crampton of bias based on his very limited involvement-- three short phone calls and being copied on one letter -- in a case roughly 14 years ago.

The hearing continues Wednesday.