"What we need to actually decide is how we're comfortable with it being used and under what circumstances."

Citizen Lab's work, paired with a report published simultaneously by Moscow-based Kaspersky Lab, helps reveal more about state-sanctioned surveillance sketched by Edward Snowden's revelations about the US National Security Agency and its international allies.

The news follows the US Supreme Court's decision that police officers will usually need a warrant before they can search the mobile phone of an arrested suspect, a major decision favouring privacy rights as concern grows over government encroachment in digital communications.

From Los Angeles to New York, and in San Diego, Chicago and Houston, law enforcement officials in the US met to discuss the ruling that could make it harder for officers to quickly find incriminating evidence. The ruling prohibits law enforcement from searching an arrestee's phone without a warrant unless a person's safety or life may be in danger.

US Justice Department spokeswoman Ellen Canale said the government would ensure federal law enforcement agents complied with the ruling.

While many of Snowden's revelations dealt with mass monitoring of communication as it flows across the globe, Hacking Team brags about more aggressive forms of monitoring that let authorities turn phones and laptops into eavesdropping tools.

Hacking Team's chief spokesman, Eric Rabe, dismissed the reports as consisting of a lot of old news. Hacking Team's ability to break into iPhones and BlackBerrys was "well known in the security industry", he said.

"We believe the software we provide is essential for law enforcement and for the safety of all in an age when terrorists, drug dealers and sex traffickers and other criminals routinely use the internet and mobile communications to carry out their crimes," he said.

Rabe invoked Hacking Team's customer policy, which says the company sells only to governments which it screens for human rights concerns. A company-established panel - whose membership Rabe declined to specify - checks out every potential client. While Hacking Team realises that its software can be abused, the policy says the company takes "a number of precautions to limit the potential for that abuse".

Those precautions haven't prevented copies of Hacking Team's malicious software being used to target more than 30 activists and journalists, according to a tally kept by Citizen Lab, a research group based at the University of Toronto's Munk School of Global Affairs in Canada.

Citizen Lab's report provided an unusual level of insight into how the malware operates, showing how devices can be compromised through booby-trapped e-mails or infected USB sticks, or even pushed onto handsets by a pliant telephone company.

Screenshots released by Citizen Lab appear to show a control panel complete with on-off switches for recording text messages, calls, keystrokes and visited websites. Other options open to Hacking Team's customers include the ability to force infected phones to take regular pictures or video and to monitor the position of an infected handset via Google Maps, effectively turning a target's phone into both a hidden camera and a tracking device.

Hacking Team built its programs for stealth. The spy software implanted on iPhones is calibrated to avoid draining the phone's battery, both Citizen Lab and Kaspersky said. On BlackBerrys, it can be programmed to ship stolen data via Wi-fi to avoid jacking up the phone bill. The spyware even comes with a special "crisis" mode that will cause it to self-destruct if it's in danger of being detected.

"The victim's got almost no chance of figuring out that their iPhone is infected," said Kaspersky malware expert Sergey Golovanov, who investigated the rogue program for his firm. Hacking Team does not say who its customers are, but researchers can draw inferences from the network of servers controlling its spyware.

In its report, Kaspersky says its scans uncovered 326 Hacking Team command servers based in more than 40 countries, including 64 servers in the United States, 49 in Kazakhstan and 35 in Ecuador. Other countries hosting multiple servers include Britain, Canada and China.

Kaspersky's report cautions that hosting a Hacking Team command server doesn't necessarily mean officials in that country are using its software, although it said that would be logical due to the complications of controlling spyware from another nation's territory.

Hints on who is using these programs can be found by studying how victims got infected.

Citizen Lab found Hacking Team software hiding in an Android phone application ostensibly designed to provide Arabic-language news from Saudi Arabia's Qatif region, the scene of protests in the wake of the 2011 Arab spring revolutions. Saudi officials did not immediately return calls seeking comment.

Steven Bellovin, a Columbia University academic who has written about hacking in the law enforcement context, described the reports' findings as credible. In an e-mail exchange, he said there was nothing inherently wrong about police using malware to infect their targets, noting that both police and criminals do carry guns.

"The hacking tools fall into the same category. They're dual use," he said.

But Bellovin said there needs to be strict rules - and open debate - about the law enforcement uses of malicious software before government-commissioned viruses are unleashed on the internet.

"None of that seems to be present here," he said.