Norwich City's new season-ticket cards have reportedly been inadvertently setting off security alarms at supermarkets in the city.

The Canaries introduced new electronic cards in the 2013-14 season and issued replacements in time for this campaign, but according to some supporters, the cards come with an unfortunate side-effect.

"It was the second time it had happened in the same store so I was about to get a talking to from the store's security department," Norwich fan David Olley told the Eastern Daily Press after causing trouble at the Sprowston branch of Tesco.

"It was only when a second security guard arrived that we got to the bottom of the problem. I carry two tickets – we removed them from the wallet and lo and behold the alarm didn't go off."

In a statement to the newspaper, Norwich said that it had yet to receive an official complaint from any of the 22,000 season-ticket holders at Carrow Road but advised fans experiencing problems to get in direct contact with the club.