The SIT investigating the infamous Bihar toppers scam on Wednesday requested banks concerned to freeze the bank accounts of all the arrested accused, including kingpin Bachcha Rai, police said on Wednesday.The other arrested in the case are former Bihar Education Board Chairman Lalkeshwar Prasad and his wife and former Janata Dal-United legislator Usha Sinha. Former board Secretary Harharnath Jha, Visheshwar Prasad and others are also allegedly involved in the case.A police official said the Special Investigation Team (SIT) had written to the regional managers of the banks concerned on the matter. The SIT had moved a local court for issuance of arrest warrants against Bihar's Class 12 Arts 'topper' Rubi Rai, who was arrested on Saturday after failing a re-test at the board's office.Ruby told police during preliminary questioning that it was 'Bachcha chacha' and her father who helped her to top the exam. On the basis of her statement, the SIT will now arrest her father, police said.So far, over 20 persons have been arrested in the case, police said.The scam surfaced after Aaj Tak TV channel showed a sting in which two Class 12 toppers could not answer even elementary questions about the subjects they 'topped' in.