TRAI reportedly calls on attorney general to examine whether operator’s free services constitutes predatory pricing.

Reliance Jio Infocomm is preparing to start charging for data once its latest special offer expires, it emerged on Thursday.

The Mukesh Ambani-owned operator has been wreaking havoc in India’s mobile market since introducing free nationwide voice and data services in September. In December, the company revealed that it was extending the duration of its free services offer until the end of March 2017.

A further extension appears to be off the table though.

Sources cited in an Economic Times report on Thursday said Jio plans to begin charging a nominal fee of around 100 rupees (€1.37) per month for mobile data. Voice calls will continue to cost nothing.

"We have to start making revenue," said one of the sources, in the report. The charge will apply until 30 June.

According to the ET, by charging a small fee for data, Jio will be able to test the loyalty of its customers, helping it to devise a more complete pricing strategy further down the line.

Meanwhile, in a separate report by The Hindu on Wednesday, it was claimed that India’s Telecom Regulatory Authority of India (TRAI) has asked the country’s attorney general to look into whether Reliance Jio Infocomm’s free services constitute predatory pricing.

Local regulations stipulate that a promotional price plan cannot last for more than 90 days, but Jio’s offer of free voice and data, which launched in early September, will remain in place until the end of March – more than six months.

Jio clearly believes it can sidestep the rule by simply relaunching the special offer under a new name every 90 days, which is what it did in December, when it announced that the "Jio Welcome Offer" would become the "Jio Happy New Year Offer" on 1 January.

Rivals maintain that its tactics are predatory. Jio on the other hand has defended itself, pointing out differences between the two promotions.

For example, the Happy New Year Offer reduced the fair usage policy (FUP) to1 GB per day from 4 GB per day, and introduced the option to pay for more data once the 1 GB allowance has been used.