Alarmed at the increasing number of fake currency notes being deposited at the cash counters of its assessment and collection department, the Calcutta Municipal Corporation (CMC) has placed orders for a dozen fake note-detecting machines.

?In the assessment department?s counters in the Gariahat office alone, we have received five fake notes in two weeks ? two in the denomination of Rs 1,000 and three in Rs 500,? said assessor and collector Soumen Maulik. Sources say the average value of fake notes deposited with CMC in a week touches Rs 15 lakh.

On any given day, the cash counters of CMC receive a substantial amount in currency notes in the denominations of Rs 500 and Rs 1,000 from the public by way of taxes, charges for issuance of various certificates and other services.

There are around 120 cash receiving counters in over 25 CMC offices across the city. But most of these counters do not have fake note-detecting machines.

?Over Rs 1.4 crore is collected daily at all cash counters of the CMC and the money is deposited in the banks,? said deputy municipal commissioner (revenue) Nandan Roy, on Tuesday.

In the absence of fake note-detectors, the civic authorities pass on the risk to the depositors by requiring them to sign a register giving the assessee number and the number of each currency note in the Rs 500 or Rs 1,000 denomination.

The objective: to track down the depositor in case the banks report fake notes. ?It is almost like looking for a needle in a haystack,? admits Maulik.

Generally, the cash is sent to the bank two days after receipt and in case of detection of fake notes, it takes another eight days for the bank to inform the CMC. The CMC then rechecks the deposition lists of the past 15 days to trace out the depositor.

Surprisingly, even after detection, the fake notes are neither destroyed by the bank nor by the CMC. Both prefer that the depositor replace the fake notes with genuine ones. Though indirectly, the banks and the CMC help the fake currency notes remain in circulation.