India has adopted recommendations strongly backing net neutrality that experts say could be the "strongest" in the world.

Net neutrality means service providers must treat all traffic equally, and not charge differently based on content.

The recommendations explicitly forbid operators from throttling data speeds for any online service, and mandates all content be treated the same.

India is expected to have 500 million internet users by June.

"Any deviations and violations of the rules of net neutrality -- which come into effect almost immediately -- will be met with stiff penalties," telecom secretary Aruna Sundarajan told Indian reporters.

The net neutrality principle is considered a cornerstone of a free and open internet that provides equal access to all and bans "any form" of data discrimination.

The country's adoption of the November 2017 recommendations by the Telecom Regulatory Association of India (TRAI) comes amid an ongoing global debate on net neutrality.

Last month, the US officially repealed rules that governed the way net providers treated the data that travelled across their networks.

The net neutrality battle
India's fight for net neutrality began in 2015, says technology analyst Prasanto K Roy.

Telecom operator Airtel was forced to withdraw a plan to charge extra for internet calls, and shut down a platform called Airtel Zero, which allowed customers to access a few mobile applications for free. Some operators call this "toll-free data", but it's popularly known as "zero rating".

Others, including Facebook and Google, were also forced to abandon their zero-rating platforms and deals. The most visible casualty was Facebook's Free Basics service, which offered Indians free access to a limited number of websites.

In March 2015, the telecom regulator published a paper on net neutrality, triggering a million emails from the public, egged on by activists who set up websites like savetheinternet.in.