Mississauga Mayor Hazel McCallion is facing allegations of conflict of interest.
City councillors voted Wednesday in favour of a judicial review of the situation.
The allegations concern McCallion's involvement in a $14.4-million land deal being brokered by her son, Peter.
It's alleged private meetings were held between the mayor, her son and the developers of a multimillion-dollar hotel project.
McCallion says she declared a conflict of interest when the matter came before council — and the council minutes support her.
But a video record of the meeting does not show McCallion declaring a conflict.
For that reason the councillors voted 6-4 to launch a judicial investigation.
It is the second time the 88-year-old mayor has come under scrutiny for conflict-of-interest allegations.
In the early 1980s, a judge ruled she breached conflict rules by being present during discussions about a rezoning issue in an area where she owned land.