The government will scrutinise electoral registration records for the first time following widespread allegations of vote-rigging in the recent district council polls.
It also says that any substantiated cases of multiple voters being registered under the same address will be referred to the police and the Independent Commission Against Corruption for further investigation.
The moves could lead to the revamping of the registration system to include options such as random checks to authenticate voters' identity, says Secretary for Constitutional and Mainland Affairs Raymond Tam Chi-yuen.
His statement came as the Registration and Electoral Office (REO) sent out 28 letters yesterday to suspect voters demanding proof of their principal residence within a week.
In the past, the government has been reluctant to employ such measures as scouring registration records and investigating individuals for fear of deterring potential voters.
Instead, it has only acted on direct complaints.
But over the past week, media and political parties have been highly critical of the registration system - which does not verify information provided by voters. They say this could lead to abuses.
Many candidates in this month's district council elections have complained about people using false information to register and vote. Most of these cases involve an unusual number of people using the same address to register. In one widely cited case in Mei Foo, 13 adults with seven different surnames listed a single flat as their permanent residence.
More such complaints emerged yesterday. In one case, a voter was found to have registered his address on a boat, while another used the address of a wet-market.
A rough count by the South China Morning Post found at least 500 possible false registration claims across 16 constituencies in the elections on November 6. The figure is based on information provided by political parties or cases reported by other media.
Only 36 such complaints were received by the government in the previous district council elections in 2007.
The sharp increase is partly linked to the surge in the total number of voters - there were 700,000 more voters this time than four years ago. It is also partly to do with raising public awareness of the problem, and greater media scrutiny.
It is hard to gauge how many of these complaints would be eventually substantiated and how this could have affected the outcome of the elections.
Still, faced with mounting pressure and criticism, the government yesterday decided to take action.
'The REO would consider ... whether anyone has provided false information which has contravened the relevant electoral laws,' Tam told the media yesterday. 'If someone has actually forwarded false information and at the same time cast votes in the district council election that will be under existing statute.
'There will be a separate legal procedure regarding questions over the election results,' said Tam when asked if the poll results would be affected if a substantial number of votes were found to be invalidated.
Voters giving false registration information face a fine of up to HK$5,000 and a maximum six months' jail.