On Tuesday, a fire that broke out on a transformer and the subsequent blast rocked the plant on the shores of the artificial Lake Suviana, owned by Enel Green Power, a unit of utility group Enel.

The explosion has heightened concerns by trade unions about workplace safety in Italy, where over 1,000 people lost their lives while working last year, according to a report by the country's national workers' compensation authority INAIL.

Divers recovered the bodies from the ruins of a turbine hall some nine levels -- 40 metres or so -- below the lake.

Rescue efforts were interrupted in the late morning of Friday after the last corpses were found, the spokesperson added.

The cause of the accident has not been established and Italian prosecutors have launched an investigation, as is mandatory in such cases.

(Reporting by Giulia Segreti; Editing by Gianluca Semeraro and Peter Graff)