(Adds details on Swiss investigations, background)
ZURICH, March 17 (Reuters) - Swiss authorities will return $70 million more from funds frozen during investigations into allegations of corruption at Brazilian state oil group Petrobras , Attorney General Michael Lauber's office said on Thursday.
The money - on top of another $120 million released a year ago - will go back to people in Brazil who suffered losses during the scandal, the statement added, without going into further details.
Allegations of bribes and political kickbacks linked to Petrobas have triggered protests across Brazil and fuelled anger against President Dilma Rousseff and members of her inner circle.
Swiss federal prosecutors say they have received reports of around 340 suspicious banking relations, opened around 60 enquiries and frozen around $800 million since 2014.
Lauber met Brazilian counterpart Rodrigo Janot in Bern on Thursday to help plan joint investigations, the Swiss prosecutor's office said.
Swiss authorities have requested documents relating to more than 1,000 banking accounts from more than 40 banking institutions, Lauber's office said.
The owners of the Swiss accounts are "senior executives of Petrobras and of its suppliers, financial intermediaries, Brazilian politicians and directly or indirectly Brazilian or other foreign companies", the office added. (Reporting by Joshua Franklin; Writing by Michael Shields; Editing by Andrew Heavens)