Elderly women are in need of more care and support, according to a report that found a sixfold surge in the number of arrests among females aged more than 60 over the past two decades.
A crime specialist said an ageing population and lack of financial support for the elderly, particularly women, coupled with rising living costs may be causing them to break the law.
Arrests in other age groups also increased, a trend that one researcher who has been studying the sex industry attributed partly to an ongoing crackdown on illegal prostitutes.
But the rise in crime among those over 60 was the most striking, policy think tank Civic Exchange said in its report.
"I suspect that for the women 60 and older, most of the arrests are to do with petty and financial crimes," said City University criminologist Oliver Chan Heng-choon, who was not involved in the report.
"Living expenses in Hong Kong are no longer low, and they have to look to other means."
Chan's theory was backed up by a breakdown of offences given by the police for the past decade. These showed that in 2001 there were 248 cases of women over 61 committing burglary and theft, while in 2011 the number grew to 926. Police said they did not have data breakdowns before 2001.
Civic Exchange researchers, using statistics published by the government, said arrests among women over 60 surged more than six times, from 204 in 1991 to 1,286 in 2011.
Although the absolute figure remained small, the increase was much greater than the population growth for this age group and faster than the rise in any other age group for both sexes, they wrote in a research paper, The Changing Faces of Hong Kong: A Cohort Analysis of Women, 1991-2011.
They also highlighted the burden of poor skills and poverty among elderly women. The median nominal monthly income for a woman over 60 in 2011 was HK$6,800, while a man in the same age group would earn HK$10,000.
Similar situations can be found in most East Asian societies where life expectancy has risen but a good welfare and care system for the elderly is lacking.
In Japan, the number of arrested elderly rose fivefold in the past 20 years, according to a Japanese government white paper on crime that did not provide a gender breakdown.
In Taiwan, the number of elderly women committing crime increased three times in eight years, police figures show.
In one case, a woman, 70, was arrested in Nantou county last year for running a drug trafficking ring. She told police she did it because "the old-age allowances are too little to support my life", the United Daily News reported.
In mainland China, female crime had grown more quickly than male crime, found a 2011 article in Criminal Research, a magazine published by the Shanghai Academy of Social Sciences. It reported a rise of 39,000 woman prisoners from 2000 to 2006, an average 15 per cent a year.
As for the rise in arrests of women aged 20 to 59, Chan said possible causes were a cultural shift in which police became less likely than before to let women off the hook, and the stress of juggling work and child rearing.
Susanne Choi Yuk-ping, a researcher on crime and women, said police crackdowns on illegal prostitutes also played a part in more women turning to crime. "In 2003, there were 10,000 women arrested who were in breach of immigration laws," she said.