Portugal’s socialist prime minister, António Costa, has resigned hours after prosecutors examining alleged corruption involving lithium and “green” hydrogen deals announced that he was under investigation and police searched dozens of addresses, including his official residence and the environment and infrastructure ministries

His announcement came after the Portuguese press reported that at least five people had been detained, including Costa’s chief of staff, Vítor Escária, and Costa’s friend, the business consultant Diogo Lacerda Machado.

The public prosecutor’s office then revealed that Costa himself was being investigated, adding the prime minister’s “name and authority” had been cited by suspects questioned during the investigation.

Rebelo de Sousa confirmed that he had accepted Costa’s resignation and would be meeting party leaders on Wednesday. The president will then have to decide whether to dissolve parliament and call an election, or whether to allow Costa’s socialists, who have a majority in parliament, to form a new government.