Swedish sympathy for slain pro-euro Foreign Minister Anna Lindh has thrown today's vote on swapping the crown for the euro wide open, with one poll on the eve of the referendum pointing to an upset "Yes" win. Police said they were "very anxious" to quiz a dark-haired man in a cap aged about 30 who was photographed by a security camera in the department store where Lindh was stabbed on Wednesday. They said he could be the killer, or a key witness.

In a sign that sympathy for Lindh might swing Swedes towards swapping the crown for the European Union's single currency today, a Gallup poll gave euro supporters a 43-42 percent lead, the first survey to point to a "Yes" win since April. But, in a bewildering span of conflicting poll results, a Temo survey indicated a clear 46-40 per cent "No" victory, little changed from before Lindh's death. A DI/Ruabs poll based on a tiny sample indicated a surge in "Yes" support to a neck-and-neck 44-44 per cent.

Yesterday, Swedish Finance Minister Bosse Ringholm predicted a "Yes" win and said it might encourage Scandinavian neighbour Denmark to follow suit. Britain, Denmark and Sweden are the only EU nations outside the euro.

Many Swedes fear that joining the euro could undermine their generous cradle-to-grave welfare system, despite the high-profile "Yes" campaign led by Prime Minister Goran Persson and big business. Stockholm police commissioner Leif Jennekvist confirmed that pictures of a man published yesterday by Swedish tabloids, with the face blanked out, were police images from security cameras inside the store around the time of the killing.