Anyone who has bought a Rugby World Cup 2011 t-shirt may have been ripped off.

Customs has intercepted a consignment of more than 1,000 counterfeit shirts carrying the official trademark branding.

Spokesman Bill Perry said the counterfeits are being sold in discount shops, markets and on the internet.

He said consumers are purchasing what they believe is the real thing but getting an inferior product.

Perry said the only way people can guarantee they are buying genuine Rugby World Cup 2011 clothing is to buy from the official licensees Canterbury or Sportfolio.

New Zealand will host the 2011 Rugby World Cup.