You don't know enough to know whether the call was legitimate. The DEA has access to the SAR you filed, but may want to view documents in your SAR file that you used in completing the SAR. That is their right, assuming the agent that visits you can document his/her identity and authority. No court document is needed in such cases.
I suggest you return the call and ask for specifics. Without confirming whether or not you filed the SAR, you can determine the purpose of the call. If it appears to be genuine, you should make an appointment for the agent to visit the bank, present identification, and review the SAR file. This should be done by whoever in your organization is responsible for coordinating your SAR filings, who presumably knows where the limits of the agent's authority to view information extend. If the agent wishes to see anything outside the SAR file, he or she will have to comply with the RFPA.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8