Finland's ministry of foreign affairs has confirmed that it has suffered a serious data breach, claiming its networks were intercepted by overseas spies.
The ministry has provided little detail on the incident, saying it applied to "the internet-based network where open information and data of the lowest classification level are handled".
Data with higher security classification is secure, the ministry said. The Finnish intelligence and security service, SUPO, has investigated the breach which has also been reported to European Union authorities.
However broadcaster MTV3 reported that the spying was discovered this spring, and may have been going on for as long as four years.
Russia and China are suspected by the Finnish authorities to be behind the network snooping, which focused on traffic between the Nordic country and EU agencies.
According to MTV3, the Finnish foreign minister Erkki Tuomioja confirmed to media last week that the breach had taken place, and that the country's intelligence service was treating it as a case of serious espionage.
"I can confirm that there was a large and severe hacking incident against the data network of the ministry," Tumioja said.
He provided no further details as to how much data may have been lost and whether the security hole has been plugged already.
MTV3 said the Finns were tipped off by the Swedish authorities about the spying.
Meanwhile, the Chinese government through their embassy in Helsinki has denied any involvement in the case.