A technical team behind the electronic poll register system, which failed during December's District Council polls, did not conduct sufficient load test on the programme, the Electoral Affairs Commission (EAC) concluded on Friday.

In a report on the citywide polls, the watchdog also recommended the Registration and Electoral Office to identify experts in fixing the system's issues and run simulations of a large-scale election regularly.

Last year, the glitch led to authorities extending voting hours by one and a half hours, and polling stations switching to printed copies of the voter register to issue ballot papers.

The report noted that design issues of the electronic poll register system caused the central processing unit to overload and unnecessarily tied up a substantial amount of resources in the server when electoral staff tried to log in to the programme.

"When altering the system design, the [Registration and Electoral Office's] technical team did not fully consider the cumulative effect and impacts on loading that might be induced to the system during actual operation, and therefore did not conduct sufficient and comprehensive load test," the report said.

The commission said the electoral office should identify suitable experts to rectify design issues and conduct "adequate, comprehensive and stringent tests", while running simulated large-scale elections on a regular basis.

"The [Registration and Electoral Office] should learn a lesson from this system failure, and actively implement the above recommendations to prevent the recurrence of similar incidents in future," it said.

"As to whether any individual officers should be held responsible for the incident, it will be followed up by the administration according to the established procedures."