COLOMBO (REUTERS) - Sri Lanka, which saw record tourist arrivals last year, said on Thursday it had started tracking those same tourists to crack down on crime and ensure national security.

The US$59 billion (S$73 billion) economy recorded one billion arrivals last year with annual revenue from tourism jumping to an all-time peak of US$1.04 billion, helped by the end of nearly three decades of civil war in 2009.

The decision to track the tourists, requiring hotels and guesthouses to submit weekly reports on their foreign guests, comes after several foreign visitors were arrested for crimes including credit card fraud and printing counterfeit money, government spokesman Keheliya Rambukwella told reporters.

"In the guise of tourists, there are certain elements which are adverse to (security of) the country," spokesman Rambukwella said.

Police in December arrested at least 100 Chinese nationals accused of an internet fraud scheme targeting people in their home country while separately, police arrested a Chinese tourist suspected of swallowing a diamond worth 1.8 million rupees (S$41,200) at the island nation's biggest international gem and jewellery exhibition.

Sri Lanka targets US$2.5 billion annual revenue from tourism with 2.5 million arrivals by 2016 and has invited international hoteliers to invest in post-war Sri Lanka.

Tourism is one of the main foreign exchange earners for Sri Lanka, along with remittances from expatriate workers, garment manufacturing and tea.