Rovio chief Mikael Hed said that the company had made great strides since deciding to view its user base as 'fans' rather than 'customers'.

"We have some issues with piracy, not only in apps, but also especially in the consumer products," he said, reports The Guardian.

"There is tons and tons of merchandise out there, especially in Asia, which is not officially licensed products."

He added: "We could learn a lot from the music industry, and the rather terrible ways ...