Norovirus struck the care home in Ljungby a week ago, initially causing the deaths of two people, with another guest dying later in the week.

Sweden’s national food agency (Livsmedelsverket) said in a statement on Monday that tests had confirmed that imported frozen fruits were the source of the sickness outbreak.

It is suspected that the raspberries became contaminated during the packing process, when boxes of berries were hand-packed by a worker who was carrying the virus.

“It is not uncommon for imported frozen raspberries to be contaminated with Norovirus,” Livsmedelsverket said in a statement on its website.