Per Jodenius, press secretary of LUF, the Liberal youth movement, has already resigned over the scandal.
Speaking at a press conference at Stockholm police headquarters on Tuesday, prosecutor Maria Häljebo said that Jodenius was currently the only person under formal suspicion of any crime.
Two computers have been impounded by police – one at Jodenius’ home and another at the Liberal Party’s offices in Stockholm.
“We have not had time to go through the computers yet,” said Häljebo.
Some relevant IP addresses had not yet been identified, she added. She said that these would be examined in the coming days.
The member of the Social Democratic youth movement SSU who gave login details to the Liberal officials will also be questioned.
“He is being questioned so that we can get some kind of framework,” Häljebo said.
The prosecutor would not say whether the SSU member was also suspected of a crime or whether he was just being questioned to provide information.
Håkan Juholt, deputy party secretary of the Social Democrats, said that the revelations would have consequences for the party’s planning.
“Of course we are going to adjust to take account of the fact that we know that others have information about our campaign planning, but I don’t want to comment on what the consequences will be,” he said.
Moderate Party leader Fredrik Reinfeldt distanced himself from the incident and was worried that it would damage the election.