Four persons have been arrested with Rs 49 lakh in demonetised banknotes of Rs 500 and Rs 1,000, police said on Sunday.
Senior Superintendent of Police (SSP) Deepak Kumar said the arrests were made on Saturday from Ram Manohar Lohiya Park in Rajendra Nagar based on a tip-off.
A Maruti car has also been seized in which they ferried the currency from Delhi to Ghaziabad.
Police said the four were waiting for an agent who would get the money exchanged when they were arrested.
The SSP said efforts were on to unearth the entire racket in which non-resident Indians (NRIs) are also involved.
While the deadline for exchanging old notes for Indians has expired, NRIs will be able to exchange demonetised Rs 500 and Rs 1,000 notes at RBI offices till 30 June.