Mr. Maran is facing charges that he had a mini-telephone exchange set up at his Chennai residence to provide 323 telephone lines to the offices of the Sun Network, owned by his brother Kalanithi.

Chartered accountant and RSS ideologue S. Gurumurthy on Friday challenged former Union Minister Dayanidhi Maran for an open debate on the BSNL exchange case. He also questioned why Mr. Dayanidhi Maran called for an early morning press meet and informed journalists just a couple of hours before.

“I challenge him (Mr. Dayanidhi Maran) for a public debate. Let him prove himself there,” said Mr. Gurumurthy who was the first person to expose this issue in June 2011. “Why did he call for a meeting at a short notice and I also want to know why he has not filed defamation case against me till date,” he asked.

Mr. Dayanidhi Maran has been facing allegations that he had a mini-telephone exchange set up at his Boat Club residence in Chennai to provide 323 telephone lines at taxpayer’s expense to the offices of the Sun Network, owned by his elder brother Kalanithi Maran. Additionally, these lines were programmed in such a way that no one other than authorised BSNL staff were aware of its existence.

A sample study, it is learnt, had estimated that 48, 72,027 units of calls had emanated from one telephone number 24371515 in the month of March 2007 alone, which is indicative of massive multimedia transfers through the connections. This, Mr. Gurumurthy said, was a great loss to BSNL.

On Thursday morning, almost 12 hours after the CBI arrested three persons — V. Gowthaman, the then additional private secretary to Mr. Dayanidhi Maran; S. Kannan, Chief Technical Officer of Sun Network; and L.S. Ravi, an electrician at Sun Network — the former Union Minister called for a press meet. He even said that technically it was not possible to have these connections.

Mr. Gurumurthy pointed out that the cables still existed. “The cables exist even now and he is lying that he has only one number. The evidence is physical in this case…,” he said.