Investigators say about 130 people have confessed to the murder of Swedish Prime Minister Olof Palme, but the case remains unsolved 25 years after he was shot on his way home from a movie theater in Stockholm.

Stig Edqvist, who heads the three-man police unit in charge of the case, says the last confession came about "a few years ago," but was dismissed along with the others.

The case would have been dropped on Feb. 28, the 25th anniversary of the shooting, but a law change last year means the investigation can go on indefinitely.

Prosecutor Kerstin Skarp admitted Monday that "we don't have any really, really hot lead right now."

The only man tried for the murder was acquitted on appeal after police failed to produce any technical evidence against him.