Authorized signatory after resignation

The Pvt ltd company run by two of its directors who sold their shares and resigned and two new directors were inducted post-retirement simultaneously( one by one ), the new board director runs a Multi level chain in the name of business of the company. The earlier two directors are the authorized signatory in the bank. The new board directors though have taken a decision to be the sole authorized signatories but have not got the bank operational details changed. The earlier directors were approached to get the accounts operated and 2CR. were transferred by their signators and net banking by them to the beneficiaries of the company in routine as has been done in past. does the old directors who operated the account can be held liable for criminal act or oppression and mismanagement. The bank has seized the account for mismanagement. what precautions does the old two directors should take to safeguard them as the NEw two directors who eventually purchased the company are misusing it to do an mlm fraud.