The Central Bureau of Investigation (CBI) on Tuesday said it had not given a clean chit to Dayanidhi Maran, the communications minister during the first United Progressive Alliance (UPA) regime, in the 2G spectrum allocation scam.

"We have not given clean chit to anyone so far, not even to Dayanidhi Maran. By September-end we may file a case and likely to complete investigation," said a CBI official.

The CBI said that during investigation, an element of "coercion" was not found against Maran, who was the telecom minister between May 2004 and May 2007, in his alleged role in the sale of Aircel to Malaysia-based Maxis group.

Maran is also accused of blocking for two years Aircel''s application for licence and spectrum with a view to pressurise its promoter C Sivasankaran to strike a deal with Maxis, a Malaysian telecom firm controlled by T Anandakrishnan, that bought stakes in Aircel later in March 2006.

It is also alleged that Aircel's file gained momentum only after Maxis, close to the Maran family, bought majority stakes in it.