At the time, Swedish security forces placed Vilks under protection while prime minister Fredrik Reinfeldt moved to diffuse tensions by calling a meeting between representatives of 22 Muslim countries over an issue which had been inflammed in 2005 by Danish cartoons of the Prophet Muhammad.
According to media reports in Ireland on Tuesday, the four men and three women are all Muslim and were arrested in Waterford and Cork following investigations carried out by European security services and the CIA and FBI in America.
"The operation... is part of an investigation into a conspiracy to commit a serious offence (namely, conspiracy to murder an individual in another jurisdiction)," said a statement from Ireland's national police service.
The seven are reported to be between 20 and 40 years old, and originally from Morocco and Yemen, but have refugee status in Ireland, where they are residents.
In 2008, Sweden's Security Service Säpo found a map of the area where Lars Vilks lived at the home of man arrested on suspicion of funneling money to terror organisations in Somalia.