Bad timing: About 3,300 pirated watches have been seized in a $4.2m counterfeit-product haul.

Customs officers have seized the year's largest haul of counterfeit goods from two export consignments at Hong Kong International Airport.

The $4.2 million haul included fake watches, mobile phones and accessories.

Officers inspected two export consignments September 16 and found 3,300 watches marked with various brand names, and 28 cartons of mobile phones, accessories and other items.

Anyone convicted of importing or exporting any goods with false trade descriptions or carrying forged trademarks is liable to five years' jail and a $500,000 fine.