Geographical constituency electors should ignore recent mail from the Registration & Electoral Office on electoral arrangements as the leaflets inside are wrongly bounded.

New mail packages will carry a stamp to indicate they have been inspected, and will reach electors before the statutory deadline, 10 days before polling day on September 12.

Chief Electoral Officer Li Wing apologised to electors who received the wrongly bounded leaflets. The office started sending out the electoral packages on Tuesday after initial random checks on the leaflets did not reveal any problems.

The mail, numbering about 290,000, is expected to reach electors in the coming days. Due to the large volume of leaflets involved, the Government Logistics Department has to farm out the printing work in batches to a number of contractors.

"We found out in ensuing checks that 12 out of 30,000 leaflets inspected were incorrectly bounded," Mr Li said.

"In view of this, we have decided to conduct a full-scale check on all the introductory leaflet of candidates before we start to send out the electoral mails again."

Mr Li said each and every ballot paper will be checked beforehand.