Police in Italy have arrested a nuclear engineer and his sister on suspicion of hacking into the email accounts of leading politicians and institutions.
They are said to have run a botnet – a network of computers harnessed without the owners’ knowledge. It is not clear what the information was used for.
The suspects’ names have not been publicly released.
Alleged victims included European Central Bank head Mario Draghi and former Italian PM Matteo Renzi.
The suspects – London residents who were domiciled in Rome – were well-known in the financial world, sources were quoted as saying by Italy’s Ansa news agency.
By planting malicious software through emails, it is thought they were able to harvest sensitive information for years.
“There were tens of thousands of email accounts hacked, and among them were accounts belonging to bankers, businessmen and even several cardinals in the Vatican,” Roberto Di Legami, director of Italy’s specialised cyber police unit, told Reuters.
Most of the hacked data was stored in the US, and is now being sent back to Italy for analysis.