Reliance Jio Infocomm Ltd has acknowledged in a police complaint that there had been a breach in its systems on Sunday, Reuters reported on Wednesday. The development comes hours after the Maharashtra Cyber Police Department detained a 35-year-old man in Rajasthan for his alleged involvement in the Jio customer data leak.

This is Jio’s first acknowledgement of the data breach, which it had denied until now.

The company’s complaint said that the accused had gained “unlawful access to its systems”, the news agency reported, quoting an unidentified police officer. The official added that the complaint had been filed in Navi Mumbai on Monday, though the telecom major did not comment on the latest news.

A team of Navi Mumbai Police and the Maharashtra Cyber Police, along with officials from Reliance Jio, are conducting searches in Rajasthan.

The breach

Customer data, including phone numbers, email address and/or Aadhaar details, were leaked on a website on Sunday. The URL was later blocked. Jio had called reports of the data leak “unsubstantiated claims”.

The mobile network has more than 120 million users in India, potentially making this the biggest data breach ever in India. However, Reliance Jio had said that its customer data is safe.