CBI could not find corroborative evidence "so far" to prosecute Mukuly Roy, Aparupa Poddar. (File) New Delhi: The CBI has found nothing "so far" against Mukul Roy, who switched from the Trinamool Congress to the BJP, and Lok Sabha TMC member Aparupa Poddar in the 2014 Narada sting tape case, while its application seeking sanction to prosecute four others including Suvendu Adhikari was pending with the Lok Sabha Speaker for over two years, officials said on Tuesday. However, they added that the investigation is still open and no clean chit has been given to anyone. The officials said the CBI had written to the Lok Sabha Speaker on April 6, 2019 for sanction to prosecute Suvendu Adhikari, Sougata Roy, Kakoli Ghosh Dastidar and Prasun Banerjee as all of them were members of the lower house when the alleged incident occurred.