Pegasus software can infiltrate a mobile phone and allow its operators to gain access to the device’s contents and files.
Finland's government says the mobile devices of its diplomats have been hacked using Pegasus spyware.
The Finnish foreign ministry stated on Friday that some of its officials abroad had been targeted by the sophisticated software.
“The highly sophisticated malware has infected users’ Apple or Android telephones without their noticing and without any action from the user’s part,” the Foreign Ministry said in a statement.
“Through the spyware, the perpetrators may have been able to harvest data from the device and exploit its features.”
Pegasus -- developed by the Israeli company NSO Group -- can infiltrate a mobile phone and allow its operators to gain access to the device’s contents and location history.
NSO says it only sells Pegasus to governments for the purpose of fighting crime and terrorism.
But an investigation last year revealed that the spyware had been used to target journalists, activists and politicians in a number of countries -- including France, Spain, and Hungary.
A recent Citizen Lab report also found that critics of Poland’s right-wing government were hacked using Pegasus.
“As you know Pegasus spyware does take the phone under its control,” said Jarmo Sareva, Finland’s Ambassador for Cyber Security.
“Even the microphone and camera of these devices were being spied on,” he added.
It was not clear how many Finnish diplomats had been targeted or which countries they were stationed in.
The Foreign Ministry said it had been investigating the use of Pegasus since last year and added that “the espionage is no longer active.”
While it says it has safeguards in place to prevent abuse, NSO says it has no control over how a client uses the product and no access to the data they collect.
The Israeli company says it has terminated several contracts due to inappropriate use of Pegasus and would cooperate with Finland's investigation.
"If and when misuse by one of our customers is identified, we will take immediate action, including termination of the customer's contract and system," NSO said.