The Cellular Operators Association of India’s (COAI) war of words with Reliance Jio has escalated again, with incumbent operators claiming the 4G newcomer has avoided paying the government revenue sharing fees by disguising full-blown mobile service as a trial.

COAI, in a letter to the Prime Minister’s Office, accused “a single operator” of evading revenue share payment, while Jio has threatened legal action for defamation, the Economic Times reported.

Jio, which is also a member of COAI, has attracted 1.5 million users to its free voice and data services in a test phase. It is expected to launch commercially later this month.

COAI said that despite earning millions by selling its own handsets, which are bundled with minutes and data, the operator has not paid revenue share to the government, the Times reported. Operators pay a percentage of their adjusted gross revenue to the government in various taxes, such as licensing fees and spectrum usage charges.

The association kicked off a row earlier in the month when it accused Jio of breaking the rules by trying to pass off commercial 4G service as a test to “potentially game policy features”. The industry group made the accusation in a letter to the country’s telecom department.

Jio in turn accused rival operators of trying to undermine its long-awaited entry into the market by deliberately not providing it with adequate interconnection points. The country’s top mobile operators rejected its request for additional interconnection points, claiming they have already provided sufficient capacity.