A group of hackers Swedish hackers calling themselves the “telecommutist cluster” say they raided the Syrian government telecommunications agency and learned it is using US technology to control Internet access, the BBC reports.

The group says the files contained evidence of “web filtering and monitoring,” indicating Syrian authorities are limiting Internet access and monitoring dissidents – and that many of the devices they scanned responded as being Blue Coat devices.

Blue Coat, a US company,  maintains it does not offer its equipment or services to Syria, and members of the hacker group say the devices are poorly configured – indicating the odds are against their having been installed or maintained by the company.

“We are actively investigating recent allegations that certain Blue Coat products have been sold or transferred into Syria and are being used by the Syrian government,” the company said in a public statement.

“Blue Coat does not sell its products into Syria, and prohibits its partners from selling Blue Coat products into Syria or other embargoed countries.”

The US imposed sanctions against Syria in 2004, prohibiting the export of US goods with the exception of medicine and food. However, the sanctions would not prevent Syria sourcing Blue Coat’s surveillance hardware from a third party in another country.

“We are concerned about reports of the use of technology by repressive regimes in general, but Syria in particular, to target activists and dissidents,” US State Department spokeswoman Victoria Nuland said.

“We are reviewing the information that we have and monitoring the facts.”

Blue Coat announced earlier this month that 85% of the Fortune Global 500 companies use its products. It also offers families free web filtering software to block pornography and gambling pages.

The United Nations estimates that around 3,000 people have been killed in Syria since a crackdown on anti-government protests began in March.