India, Feb. 18 -- Police in Karnataka's Udupi district have arrested a fourth suspect in an investigation into the alleged transfer of sensitive Indian Navy information to contacts in Pakistan, widening a case that authorities say involves employees linked to a shipbuilding facility at Malpe port.

The latest accused, identified as 21-year-old Alif Islam from West Bengal, was arrested from Marayur village in Kerala's Idukki district. Investigators are examining his background amid suspicions of possible foreign links.

The case was registered at Malpe police station after allegations surfaced that individuals associated with a unit of Cochin Shipyard Ltd had shared confidential naval information through WhatsApp and Facebook. The material...