Postal Services Director Manoj Kumar and Senior Superintendent of Posts Sanjay Akhare, both serving here in Ahmedabad Head Post Office, were arrested after a case was registered against them and others on March 7.
A CBI court of Special Judge S J Raje sent the duo to the CBI custody till March 23.
The investigating agency had filed an FIR against them and other unknown persons after it was revealed that Rs 6,59,800 was exchanged on November 9, a day slated for no financial transactions, at Navrangpura Head Post Office, a day after the demonetisation decision was announced, said the CBI.
There were many other contradictions too in the ledgers books for the inflow and outflow of the currency notes, it said.
The investigation revealed Kumar had exchange Rs 80 to 90 lakh demonetised currency notes unauthorisedly, while Akhare had exchanged Rs 13 to 15 lakh, an official said.