(Adds 5-Star comments)
MILAN, Dec 16 (Reuters) - The governments of Italy’s two biggest cities came under judicial scrutiny on Friday, with Milan’s mayor suspending himself from his duties and a top aide in Rome’s administration put under arrest.
Milan Mayor Giuseppe Sala said late on Thursday he had learned from the media that he was under investigation in a case involving tender bids at last year’s Expo world fair.
“While I have not the slightest idea of the investigative allegations, I have decided to suspend myself from my position as mayor,” Sala said, six months after taking over at Milan’s city hall.
In Rome, a judicial source said Raffaele Marra, an aide to Mayor Virginia Raggi of the 5-Star Movement, was arrested on Friday on suspicion of corruption linked to a 2013 real estate deal.
The current administration is not implicated, the source said, but the arrest is the latest in a series of headaches for Raggi.
Sala, who was backed by the Democratic Party headed by former Prime Minister Matteo Renzi to become mayor of Italy’s financial capital, was in charge of Expo Milan 2015.
Preparations for the event were blighted by a corruption scandal that led to the arrest of several top officials in 2014, laying bare the spread of mafia groups from their southern fiefdoms to the wealthier north.
Raggi has been beset by resignations and infighting since winning the June election, when 5-Star, which was founded by comic Beppe Grillo, took on its biggest challenge yet as managers of the corruption-tainted capital.
Raggi, whose party campaigns on promises to break with an establishment widely seen as corrupt, had originally named Marra as chief of staff before moving him to a human resources role.
After 5-Star lawmaker Roberto Fico said the arrest was “a very serious thing” early on Friday, Raggi apologised to voters and the party, but rejected calls by opposition politicians that she should resign.
“We trusted him (Marra); probably we made a mistake,” Raggi said. “We apologise to Romans, to 5-Star supporters and to Beppe Grillo, who had expressed doubts” about Marra, she said.
Carabinieri police searched Marra’s office on Friday morning, the source said, a day after they seized documents at city hall relating to the hiring process in the city administration. (Reporting by Stephen Jewkes and Isla Binnie, additional reporting by Massimiliano Di Giorgio and Steve Scherer; Editing by Larry King)