The incident happened yesterday evening when CISF Sub-inspector Herkewal Singh noticed an unclaimed bag lying at the X-ray scanning machine at New Delhi metro station.
The official immediately segregated the bag for a second scanning and it was found that the bag contained a cash of Rs 1.20, a senior official said.
A Palam resident, identified as U K Jain, later came back to claim the bag from Metro authorities, which was returned to him after due verification.
"Jain said he forgot to collect the bag after he put it on x-ray scanner," the official said adding Jain gave a written note to thank the Central Industrial Security Force and Delhi Metro staff.