A thirty-year old Oulu man was jailed on Wednesday for attempting, last year, to extort money from the Zeppelin Centre branch of Prisma by threatening to expose customers and staff to serious health risks.

The man's menacing demand for 100,000 euros led to the branch of Prisma being closed for over a week while the police looked for the suspect. The Zeppeline Centre itself was forced to close for four days.

The man threatened to poison various products in the shop if his demands were not met. Prisma was shut in August last year so that the police could investigate whether or not the man had carried out his threat but nothing appeared to have been poisoned.

The man eventually confessed to sending the threatening letter. According to investigating officer Seppo Rautava, the man's motive was purely financial - to extort as much money as possible from the supermarket. However, he had not contacted any other supermarket in that chain or any other customers or employees.

The man was sentenced to six months behind bars.