Updated

The head of Italy's anti-establishment 5-Star Movement has offered public support for Rome's mayor after she was placed under investigation by prosecutors for a problematic city hall appointment.

In a blog post Thursday, 5-Star leader Beppe Grillo said Virginia Raggi was calm "and I can't but be close to her at a time that I know is very difficult."

Raggi is to be questioned next week about the appointment of Renato Marra as director of Rome's tourism department. Marra's brother headed city hall's personnel office until he was arrested in a corruption probe last month.

Raggi has said that she alone decided Marra's appointment, but phone intercepts indicate the brother played a behind-the-scenes role.

She has said she is confident in the justice system and ready to cooperate with prosecutors.