A revolver that Swedish police believe may have been used in the unsolved murder of Swedish Prime Minister Olof Palme in 1986 has been recovered.
Palme was gunned down after visiting a cinema in 1986
The gun - a Smith and Wesson revolver - was found in a lake in central Sweden and handed over to police.
Palme was shot on 28 February 1986 on his way home from a Stockholm cinema.
The only man tried for the murder, a petty criminal and drug addict Christer Pettersson, was acquitted on appeal for lack of evidence. He died in 2004.
The recovered revolver was used in a 1983 post robbery in Mockfjard, a town near the lake where it was found, said Stig Edqvist, a member of the Palme investigation team.
Police tests had previously showed that the chemical properties of the bullets used in the Mockfjard raid matched those of the bullets found at the scene of Palme's murder.
"We have found a weapon we have long been looking for," he told reporters.
He said its serial number matched that of the gun dubbed the "Mockfjard weapon".
But he added that "we don't know if it is possible to confirm or reject" that the gun was the Palme murder weapon.
The Swedish news agency TT reported that the weapon was damaged, and that, according to a forensics expert, the key question for the investigation was whether it could still be fired.
The revolver was found by divers who acted on an anonymous tip-off to Sweden's tabloid Expressen.
Police had previously conducted seven unsuccessful dives in the lake to try to find the gun.