The "Occupy Central" movement hindered the Hong Kong Police Force from solving crimes - forcing the number of successful cases to drop by over 2,000 last year, Commissioner of Police Andy Tsang Wai-hung said on Tuesday.
The number of cases solved in 2014 stood at 29,400 while the 2013 figure was 31,498, according to the city's annual report on crime.
Many police officers had to drop what they were doing to deal with the "Occupy" protests. The large illegal campaign had required considerable police manpower, added Tsang.
But despite this, the city remained one of the safest in the world. In a report compiled by British think tank Legatum Institute, Hong Kong topped the urban safety index. The World Justice Project, an independent organisation working to advance the rule of law, said in its 2014 report that Hong Kong ranked fourth in the world.
The city's overall crime dropped 5,171 from 72,911 in 2013 to 67,740 in 2014 - a record low since 1997.
Crimes per 100,000 population dropped 7.7 per cent to 936, the first time since 1973 that the number fell to less than 1,000, according to the report.
But Tsang said Hong Kong could not afford to be complacent. "A growing sense of lawlessness among people may do great harm to law and order in the long term," the commissioner warned.
Recruitment of new police officers has not been hurt by "Occupy". Some 1,130 people attended a recruitment fair organised by the Hong Kong Police Force last December. This was an 8 per cent rise compared with 2013, police statistics showed.
Tsang pledged to train officers to better handle unauthorized assemblies. Police would always deal with any illegal activities in accordance with the law, he said.
He also called for "mutual trust" between police and Hong Kong people - where police strictly enforce the law and people abide by the law.
Legislator Priscilla Leung Mei-fun said Hong Kong police showed a more professional approach than those in other countries when dealing with protests. She expressed the hope that the police would review its manpower resources to enforce the law.