The Electoral Affairs Commission has declined to investigate a challenge to the polling result of the Regional Council constituency.
In a letter to defeated candidate Ann Chiang Lai-wan, chairman Mr Justice Woo Kwok-hing said her challenge to the returning officer's decision could only be handled by the courts.
Ms Chiang lost by one vote to the Progressive Alliance's Dr Tang Siu-tong.
She claimed four ballot papers should have been invalidated by the returning officer because they were not marked with Arabic numerals as required.
But the commission said under election regulations it had no power to overturn the returning officer's decision.
Ms Chiang said she would consider her next move in the coming week. 'I believe the law and electoral system are fair and will fight for the right election results via all proper legal channels.