One of the construction companies that built the West leg of Calgary's LRT line has launched a lawsuit and says it hasn't been fully paid for the work.

CTV Calgary Consumer Watch Specialist Lea Williams-Doherty looked through the court documents and says Lafarge Canada has sued the City of Calgary's contractor, which is a consortium of SNC Lavalin and Graham Companies, for more than $9.2M.

Lafarge Canada says it has tried to collect for more than a year and been unsuccessful so now it has filed a lawsuit.

Lafarge alleges that it originally agreed to do the job for $16M but then the contractor increased the scope of the job so it agreed to pay Lafarge's additional fees and costs.

Lafarge says the tab came to more than $28M and that it has been trying to collect the last $9M since February of 2013.

SNC Lavalin declined to comment on Lafarge's allegations and Graham Calgary didn't return Lea’s call.

Leas says the city told her that  it is not directly involved in the dispute and was simply named as the owner of the LRT.

The defendants have yet to file a response and it is too soon to tell what effect this may have on city coffers.

(With files from Lea Williams-Doherty)