0653 GMT March 21, 2018
The general prosecutor's office said in a statement on Wednesday that Socrates was indicted on 31 bribery charges and other crimes, including money laundering, tax fraud and falsification of documents.
Lawyers for Socrates called the accusation "baseless," saying in a statement that they intended to use "all legal means" to defend the former socialist premier.
The 4,000-page indictment, which also targets 18 other individuals and nine companies, accuses Socrates and his accomplices of accumulating an estimated fortune of more than 24 million euros ($28 million) in Switzerland, in exchange for favors granted to several firms, including the Espirito Santo bank that went bankrupt in summer 2014 amid accounting irregularities.
The crimes were allegedly committed between 2006 and 2015.
Socrates, who was prime minister from 2005 to 2011, was arrested in 2014 and spent nine months in prison before being shifted to house arrest in 2015.
The 60-year-old former political leader denies any wrongdoing.