Toronto's auditor general will look into a complaint lodged by a group of transit riders that alleges city council was given misleading information when it voted to forge ahead with plans for the Scarborough subway extension last summer.

Beverly Romeo-Beehler said her office won't comment publicly to protect the integrity of the case, but said her office assesses every allegation it's given.

The Scarborough Transit Action group alleges the TTC provided a briefing note last July that inflated the cost of the seven-stop light rail plan to around $2.7 billion to persuade council to go with the subway option, instead. 

City council voted 28-15 against reverting to the LRT option for replacing the aging Scarborough RT line. The complaint says council lacked the right evidence to make that decision. 

Following the vote, Mayor John Tory said the result proves the subway-versus-LRT debate is over, and that Torontonians want the city to get on with building the new subway extension, which is now expected to cost some $3.2 billion.

The project would extend the Bloor-Danforth subway line from its current eastern terminus at Kennedy station one stop to Scarborough Town Centre. 

Brenda Thompson, of Scarborough Transit Action, said she still thinks the LRT is the best plan and will serve the most riders. She's hoping the auditor general's findings will prompt council to take another look at the plan, although she admits it will be difficult.

"The majority of councillors in Scarborough are in favour of the subway, there's a lot of misinformation out there about LRT — we're up against all of that," Thompson told CBC Toronto.

"Let's face it, it's not going to be easy."

TTC defends staff

When asked about the complaint, TTC spokesman Brad Ross said TTC staff are committed professionals who provide information on a range of complex issues.

"In all that it does, staff has never wavered from its deep-seated commitment to excellence in public service, openness, transparency and integrity," he said in an email.

Thompson said if the auditor general's finding doesn't change city council's mind, she hopes it will at least change the way Toronto approaches major transit decisions in the future.

"Public confidence in our ability to build transit for transit riders is pretty low right now," she said.