Beijing's top man on Macau affairs has issued a "you are being watched" warning to mainland officials who still fancy taking a chance at the city's casino tables. As pressure on Macau to clean up and diversify its casino-dominated economy continues - part of President Xi Jinping's wide ranging "tigers and flies" crackdown on corruption - Li Gang, the director of the city's liaison office there, said measures were in place to ensure that officials who head for the former Portuguese enclave "would be discovered". The top official did not elaborate on what specific measures had been introduced but it is common knowledge that identity checks are now carried out on every person who gambles in casino VIP rooms. Macau's casinos are known as a key mechanism by which corrupt officials launder funds. In his first public comments this year on Macau's gaming industry, which has suffered an unprecedented slump in recent months due to the anti-graft drive and a general economic slowdown on the mainland, Li told The Beijing News : "As the crackdown on graft is stepped up, some corrupt officials - including executives of some state-owned enterprises - now dare not go to Macau to gamble. "Moreover, because of measures taken by Macau's gambling industry, if such officials go gambling in Macau, they will be discovered." Li also said it was time for Macau and the mainland to establish an agreement that would ensure the repatriation of officials found to have been up to no good in the world's biggest gaming destination. "It's necessary for both sides to strengthen cooperation in this field. Once any criminal fled to Macau with money, the Macau authorities could repatriate [him], so as to jointly crack down on crimes," Li said. "So far, there is a discussion mechanism in place between Macau and the mainland, but there is not any repatriation agreement, which should be sealed as soon as possible." In January, the South China Morning Post reported that an extradition treaty between Hong Kong and Macau was in the pipeline, under which fugitives who took refuge in one city to avoid punishment in the other would be sent back. Li also revisited comments he made in December last year about Hong Kong and Macau and their adherence to the Basic Law, in the wake of the Occupy Central protests. "I think it's very important to boost national education among the young people in Hong Kong and Macau," Li said, adding: "Students are the majority group of Occupy Central. "They don't understand the reality of China, or they don't understand well so-called Western democracy and the reality and history of China."