India's telecoms authorities are blocking widely used file storage websites such as Megaupload, Rapidshare, Mediafire and Putlocker, according to reports on several user forums.
Internet service providers MTNL, BSNL and Airtel have confirmed difficulties in accessing these sites, according to US reports.
The reports say the decision behind blocking the websites appears to be piracy. Most of the websites affected are widely used to share film and music content.
The reports come within a day of India signing a memorandum of understanding with the US to collaborate on cyber security issues.
The US Department of Homeland Security has made similar moves against piracy by seizing domains of websites hosting pirated content.
The cost of piracy to the Indian entertainment industry was estimated at between $1 and $2 billion, according to local reports.