CBI sources said despite repeated requests they have not received complete set of documents from West Bengal Police related to the scam, raising fears that some of these documents might have been destroyed.
They said in case it is established that crucial documents related to the scam were destroyed by the officials intentionally, the agency might proceed against them for the destruction of evidence.
The sources said CBI understands that vast number of cases were registered by West Bengal Police while probing the scam in which thousands of poor people's money was allegedly siphoned off by masterminds of the chit fund schemes and collecting all the documents will be difficult.
They said the agency is giving the police enough time to provide it with all the material related to the scam which has been collected during the probe by the state police.
The sources said the agency is aware that some police officials are under pressure from influential people and that it is keeping a close watch on such suspicious people.
"Such high profile people are alleged to be part of the scam. It is but obvious that police would be under tremendous pressure. We are keeping a close watch on the developments," said a senior official.
A senior official supervising the probe said CBI might register additional cases in West Bengal and even examine a famous actor in connection with the scheme.
The CBI, on the directions of the Supreme Court, recently began its probe in the scam in which it has registered three cases in West Bengal and over 42 cases have been registered in Odisha.