The three, including a retired police constable, were taken into custody following information about their suspicious activities. However, police declined to provide further details about their identity.
Five Maoists, including Roopesh, wanted in at least 20 cases in Kerala, and his wife Shyna, were arrested last month from Karumathampatti near here.
Police said they had information that the five had given training to some people from Kerala, Karnataka and Andhra Pradesh.