Sri Lankan police have arrested six persons, including an Indian national, in connection with a counterfeit currency racket.

Officials said the six were arrested after a money changer noticed that the 500 and 1,000 Indian rupee notes presented to him for changing were fake.

"We have recovered 16,000 fake notes in the 1000 rupee denomination and 21,400 in the 500 rupee denomination," a police official said.

Investigations are underway to trace where the counterfeit operation was carried out, police said, adding that initial suspicion was that they might have been printed in India.