The National Investigation Agency (NIA) on Monday arrested one more accused in connection with the Visakhapatnam espionage case after raiding two locations in Mumbai, the agency said.

The case involved the leakage of classified defence-related information through a Pakistani ISI spying network, the NIA said in a statement.

With the arrest of Amaan Salim Shaikh from Mumbai, the number of the arrested persons so far has gone up to three, it said.

The NIA has already charge-sheeted four persons, including two absconding Pakistani operatives, in this case, it added.

While on the hunt for the wanted accused, the NIA on Monday conducted raids at two locations in Mumbai and at another location at Hojai in Nagaon district of Assam, the agency said.

Shaikh was found involved in the activation of SIM cards that were being used by Pakistani intelligence officers involved in the racket, it said.

The racket first came to light in 2021, when the Counter Intelligence Cell, Andhra Pradesh, registered a case on January 12 that year under sections 120 B (criminal conspiracy) and 121A (Conspiring to commit certain offences against the State) of the Indian Penal Code, sections 17 and 18 of the Unlawful Activities (Prevention) Act, 1967, and section 3 of Official Secrets Act, 1923.

The NIA took over the case in June 2023 for the investigation.

On Monday, NIA teams seized two mobile phones from the location where Shaikh was arrested, while two more mobile phones and a host of sensitive documents were seized from other locations during the raid.

The NIA had filed a chargesheet on July 19 against two accused, including an absconding Pakistani national, Meer Balaj Khan.

Investigations had revealed that Khan and other arrested accused Akash Solanki were part of an espionage module procuring and leaking sensitive vital information pertaining to the Indian Navy to Pakistan-based handlers, as per the statement.

The NIA on November 6 filed a supplementary chargesheet against two other accused persons, identified as Manmohan Surendra Panda and Alven. While Panda was arrested, Alven, a Pakistani intelligence operative, is absconding, as he is based in Pakistan, it said.

Investigations are continuing in the case and custodial interrogation of Shaikh is expected to yield more leads in the conspiracy relating to attempts by foreign-based elements to obtain sensitive and classified information relating to defence establishments across the country, the agency said.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.