Besides mobile phones and laptops, some similar clues have also been obtained from the desktop at Ghosh’s office at RG Kar College and the paper documents seized from there, sources aware of the development said.

Investigation so far, sources added, has revealed a three-tier nexus in the RG Kar financial case, where the first tier involves these politically influential patrons of Ghosh which made him so desperate.

While Ghosh and his extremely close associates were in the second tier in the case, the third and final tier involved those contractors and suppliers to RG Kar who were extremely close confidants of Ghosh.

Sources added that the parallel investigation by the Enforcement Directorate (ED) in the case too has identified some money trails that confirm this three-tier nexus in the case.

While CBI’s investigation in the RG Kar financial irregularities case is court-directed and court-monitored, ED had made a suo motu entry in the matter after filing an Enforcement Case Information Report (ECIR).

Both the investigative agencies, sources added have identified a pattern in the modus operandi of the case which involves manipulation in the tendering system for awarding contracts or work orders, getting infrastructure-related work done by outsourced agencies instead of the state public works department, illegally selling bio-medical wastes from the hospital in open markets and smuggling of organs of unidentified bodies coming at the hospital morgue.

The investigative officials have also identified the role of a number of shell companies opened to carry out the money laundering in the case, which is quite similar to the West Bengal school job case and ration distribution case.