Official sources said that the investigating agency has gathered sufficient evidence against these members for allegedly "conspiring with private persons to pass favourable orders".
The ITAT is a quasi-judicial body and has benches at Mumbai, Delhi, Agra, Ahmedabad, Allahabad, Amritsar, Bangalore, Chandigarh, Chennai, Indore, Nagpur, Patna among others.
The two-member bench is selected by a board chaired by a sitting judge of the Supreme Court.
"The CBI has received evidence on alleged irregularities being done by ITAT members. Over 50 orders passed by these members are being scrutinised by the agency. The orders clearly indicate criminal collusion and corruption," a source claimed.
He said the names of some noted chartered accountancy firms have also come up during the preliminary investigation.
"Some fresh cases may be registered against ITAT members and personnel of the chartered firms," the source added, refusing to divulge more information.
The CBI had on May 13, 2008 registered a case against Jugal Kishore, an ITAT member from Kolkata, for allegedly accepting a bribe of Rs 30 lakh from an accounting firm to deliver favourable orders to its client. (MORE)