"In the guise of tourists, there are certain elements which are adverse to the country. That is why we need to keep a track of them," Keheliya Rambukwella, minister of information and government spokesman told reporters.
Last week, the police headquarters had told local police stations to gather information on tourists lodged at hotels and guest houses within the respective police areas.
The police said the measure was taken for the safety of tourists.
A British tourist was killed in an attack at a southern tourist resort in December 2011.
The government has lodged its protest against the British travel advisory saying Sri Lanka saw the arrival of over a million tourists in 2012.