In a big blow to Kalanithi Maran owned Sun TV, 33 channels of the group have been ordered to go off air. The order comes after a security clearance was refused by the Ministry of Home Affairs to the channels.

The security clearance has been denied on the basis of an ongoing probe against Maran by the Central Bureau of Investigation (CBI) and the and Enforcement Directorate (ED). Sources say that the Information and Broadcasting Ministry wrote a note in favour of Maran to give a clearance but the MHA refused it.

Sources in say that I&B Ministry will ask for a review from the MHA after seeing the order. They also said that there is a provision of going to court by affected parties.

While Sun TV claimed that they have not received any notification from Home Ministry, they also added that they will seek legal help. "We will definitely seek legal recourse if our licence is revoked," Sun Group CFO SL Narayanan said.

Soon after the order, the stocks of the channel tanked by over 20 percent.

The Sun TV Network is one of India's largest media groups whose TV channels reach more than 95 million households in India. The Network had applied to the Information and Broadcasting Ministry for renewing its broadcasting licence for 10 years. The process required security clearance from the Home Ministry.

Earlier, the Home Ministry had denied security clearance to 40 FM radio stations run by the Sun Network, prompting Information and Broadcasting Minister Arun Jaitley to write to Home Minister Rajnath Singh in April, seeking a review of the decision. However, there has been no change in Home Ministry's decision.

The Sun Network had already moved the Madras High Court seeking interim relief in the Sun FM matter and the court has granted it a stay till the petition is disposed of. It is expected to move the court again in the Sun TV Network issue.

The Maran brothers, nephews of DMK patriarch M Karunanidhi, are facing a CBI probe over alleged allotment of 300 high-speed BSNL telephone lines to the residence of former Communications and Information Technology Minister Dayanidhi Maran in Chennai which were extended to his brother's channel.

There are two other pending criminal probes against Sun TV Network and its owner Kalanithi Maran - CBI's Aircel-Maxis case and an Enforcement Directorate case of money laundering.