The concept of a self-contained network has been reverberating within Iran for almost a decade and has often been treated with skepticism, given the significant investment in infrastructure and security that would be required. But Iranian officials and outside experts say that development of the network has accelerated following cyberattacks aimed at the country’s nuclear program…

At the core of the network was high-end equipment manufactured by the Chinese firm Huawei that is capable of sophisticated online surveillance of traffic. The network is already “internally consistent and widely reachable,” concluded the report, a copy of which was provided to The Washington Post.

The findings are likely to worry Internet freedom activists and the Obama administration, which has spent tens of millions of dollars on initiatives designed to ease access to the Internet in Iran and other countries with repressive governments. Officials had expressed concerns even before the release of the latest research.