Enforcement Directorate sleuths have stalled an attempt by Pakistan's ISI to pump fake Indian currency notes into the country through a new route -- Colombo to Chennai -- and arrested four persons in this connection.

The sleuths arrested Shekh Abdul Qadar and recovered from him fake currency with a face value of Rs 45 lakh.

He had received the consignment at Colombo, where the fake money had been sent via Dubai, highly placed sources said on Wednesday.

Following his interrogation, three more men -- Rafiq, Abdul Nasir and Dhansu -- were arrested from different parts of Chennai earlier this week.

They were produced before a court that remanded them to the Enforcement Directorate's custody for interrogation.

According to the sources, Qadar told interrogators that counterfeit notes with a face value to Rs 5 crore had arrived in Colombo from Dubai and there were plans to smuggle the consignment into the country for its subsequent distribution in the Indian market.

A vigil has been mounted at all entry points from Colombo and the information has been shared with the Coast Guard, which is keeping a strict vigil on all smuggling routes to the country, the sources said.

The new ploy of using Colombo to transport the counterfeit currency is believed to have adopted by the ISI after a decrease in the number of points for the agency to pump in fake notes into India, the sources said.

Traditional modes for smuggling forged currency like the Samjhauta Express train and routes on the border with Nepal had been exposed due to the sustained efforts of security forces, they said.