The opening of the 14th edition of Venice’s Architecture Biennale has been overshadowed by the arrest of the city’s mayor and 34 other politicians and businessmen, reports the Art Newspaper.

Venice’s mayor since 2010, Giorgio Orsoni has been charged with embezzlement, money laundering, and contract rigging related to a massive construction project that plans to erect flood barriers around the city. The €7 billion ($9.5 billion) MOSE Project, designed to protect Venice in the event of a severe flood, is scheduled to be completed in 2016.

A larger corruption probe conducted by the Italian financial police in connection with the project has investigated more than 100 people, and 34 others have also been detained. The mayor is currently under house arrest, but his lawyers have assured the press that his arrest “lacks credibility.”

Among the others who have been arrested are regional assessor for infrastructure Renato Chisso, regional councilor for the Partito Democratico Giampietro Marchese, and Emilio Spaziante, a former general in the army. Also among those arrested are two former presidents of the Magistrato alle Acque, which was once hugely influential in its governance of the Venetian lagoon, but is now a minor department in the ministry of pubic works.

Investigators have also moved to arrest Italian senator Giancarlo Galan, who previously served as governor of the Veneto region (1995–2010) and as the Italian minister of culture in 2011. A majority of senators must vote to approve the arrest for the police investigators to be able to move forward with the case against Galan.

Three years ago, investigators realized that construction company Mantovani’s director, Giorgio Baita, was laundering some €20 million ($27.2 million) in public MOSE funds through foreign bank accounts in the Republic of San Marino. Allegedly, he was assisted by Claudia Minutillo, formerly Galan’s personal secretary.

Despite the legal controversy, the MOSE construction project is still moving forward, and several barriers underwent successful tests last year.