The European Union's data protection watchdog (EDPS) has called for a ban on the controversial Pegasus spyware.
The authority said the software may lead to an "unprecedented level of intrusiveness, able to interfere with the most intimate aspects of our daily lives".
A ban on its development of the EU would be "the most effective option to protect our fundamental rights and freedoms," the EDPS added in a statement.
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 a media 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, while Finland's government says the mobile devices of its diplomats were also targeted.
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.
"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," the Israeli company has said.
On Tuesday, the European Commission also condemned all forms of illegal device hacking following the Pegasus scandal.
EU Justice Commissioner Didier Reynders told the European Parliament that national security cannot be a "blank cheque" for not respecting citizens' fundamental rights.
"Any attempt by national security services to illegally access the data of individuals, be they lawyers, journalists, prosecutors, civil society activists or political opponents, is completely unacceptable," he said.
Reynders reiterated that the EU was closely monitoring an investigation into whether the software had been used illegally by the Hungarian and Polish governments.