Mobile internet usage in India has increased ninefold in a single year, after the launch of a new operator sparked a telecoms price war, according to a new report.

Indians used nearly 1.3 billion gigabytes of data in March 2017 compared with around 150 million in the same period last year, said the report, Internet Trends 2017, published this week by the US investment fund Kleiner Perkins. The explosion in data use comes after the country's richest man Mukesh Ambani, shook up the telecoms market with the launch of new operator J io in September.

The 4G telecom operator launched with an offer of free service for the rest of the year, followed by vastly cheaper data plans and free voice calls for life. That led to a dramatic fall in the average cost of mobile internet in India, which the study said was 1.9 dollars in March compared to 4.4 dollars three years earlier.

By March this year Jio had 108 million subscriber, and was charging just 17 cents per giga of data.

Despite regulatory and technical obstacles, India's mobile internet market has huge growth potential with hundreds of millions expected to get online over the next decade using smartphones. The country counts one billion mobile phone users, but nearly three-quarters of its population lacks access to the internet. In 2016, only 350 million Indians were able to go online.