Swedish prosecutors next week will decide to speed up or close the investigation of the murder of Prime Minister Olof Palme in 1986.

"Chief prosecutor Krister Petersson will announce his decision on June 10, and at the same time speak about the case with Hans Melander, the head of the investigation," the Swedish prosecutor said in a statement.

The late Prime Minister Palme, 59, was assassinated on February 28, 1986 after leaving a movie theater in Stockholm.

Over the years, more than 130 people have voiced responsibility for the assassination.

Christer Pettersson, a drug addict who often committed petty crimes, was convicted of murdering Palme in July 1989, after being identified by the late Prime Minister's wife.

Investigators have also been skeptical of the Kurdish Workers Party, a Turkish armed group considered a terrorist organization, even the Swedish army and police or South African secret service, but

Experts and Swedish journalists recently said that the most likely scenario for the case is to close the investigation, because the main suspects rumored in the media are dead.

The late Prime Minister Palme strongly opposed the US war in Vietnam, supported the governments of Cuba and Nicaragua, and spoke out against racism and nuclear weapons racing.