Rewards amounting to nearly HK$10 million, put up by police as early as 1997, remain on offer with more than 20 culprits still on the run. The police website lists 25 rewards amounting to HK$9.95 million for killers, robbers and acid throwers.
The highest reward, HK$2.5 million, is being offered for information leading to the arrest of robbers and the recovery of HK$11.7 million in cash and valuables stolen from three safes in the office of Feoso Oil in Cheung Sha Wan last year.
The stolen property includes dozens of watches, about 200 Canadian maple leaf gold coins and jewellery.
The second-largest reward, HK$800,000, is for information leading to the arrests of four Wo Shing Wo triad members wanted over the death of Lee Tai-lung, head of the Tsim Sha Tsui faction of the Sun Yee On triad.
Lee, 41, was rammed by a car outside the Kowloon Shangri-La Hotel in Tsim Sha Tsui in August 2009 before being hacked to death.
The third biggest reward is H$500,000 for the recovery of a 16.83-carat emerald ring worth HK$12.2 million that vanished in seven minutes after being left in a washroom at the Four Seasons Hotel in Central in September 2011. It is owned by Caroline Scheufele, co-president of the Swiss luxury watch and jewellery company Chopard.
A reward of HK$300,000, posted on the police website last month, is being offered for information about the killing of a restaurant manager, Kwan Tak-ming, 44, who was shot three times at close range outside his restaurant in Chai Wan in 2001. Despite the offer of a HK$400,000 reward for information about the firebombing of the Top One karaoke lounge in Tsim Sha Tsui in 1997, two suspects - Chan Wai-leung, known as Mei Mei, and Chan Fok-ching, known as Ah Ching - are still being sought. Seventeen people were killed and 13 others injured in the incident.
Police have also offered four rewards totalling HK$1.2 million for help in solving four acid attacks in Mong Kok and Yau Ma Tei between December 2008 and January 2010 that injured 131 passers-by. No one has been arrested.
No reward is being offered in connection with the killing of 30-year-old nightclub hostess Wang Rong, whose body was found in a suitcase in Victoria Harbour in April last year. Police are looking for her boyfriend who is believed to have gone to the mainland.
"We offer cash rewards when we have no clues to the cases," a veteran detective said.
A police spokesman said "the consideration for offering the rewards, as well as the amount, will depend on the circumstances and suitability of the case".
Police would not reveal how many rewards had been paid in the past 10 years.