Montreal mayor Gérald Tremblay cancelled a scheduled public appearance Friday afternoon as questions surrounding a dubious real estate transaction continue to hound his office.

Tremblay was supposed to give a speech for the 20th anniversary of the Défi Canderel (Canderel challenge), a corporate fundraiser for cancer research. But his office said he wouldn't be able to make it.

The cancellation comes the same day as the influential La Presse newspaper called for Tremblay's retirement from politics, as the city gears up for municipal elections six months from now.

Tremblay has come under fire after a second report from the city's auditor's office suggested Montreal's general manager, Claude Léger, was fully aware of risks surrounding the controversial Faubourg Contrecoeur project, which involved the sale of land far below market value.

In 2007, Montreal's Housing and Development Corporation (SHDM) sold the land to Construction Frank Catania for about $4 million even though its market value was $31 million. The sale netted a $5 million loss for the city, according to the auditor.

The report echoed findings detailed in an earlier report from the auditor’s office, made public Tuesday, that investigated 20 real estate transactions in which rules were violated or ignored altogether.

The mayor has defended Léger, saying he’s satisfied with his answers regarding questions raised in the auditor’s report.