CBI wants Anil, Tina Ambani as witnesses in 2G case Seeking to make Reliance ADAG chairman Anil Ambani and his wife Tina Ambani prosecution witnesses in the 2G spectrum allocation scam, CBI on Tuesday told a trial court that their deposition was required as the executives of the company who are accused in the case had not given "clear-cut answers" as to at whose instance they floated a shell company to bag spectrum.