A team of Swedish investigators has gone to a Turkish prison island to interview the Kurdish rebel leader Abdullah Ocalan about the assassination in 1986 of the Swedish Prime Minister Olof Palme.

The team wants to ask Mr Ocalan about allegations he has made that a dissident Kurdish group killed Mr Palme.

It is now 15 years since Palme was shot dead on a Stockholm street as he walked home from the cinema with his wife.

There have always been several conspiracy theories swirling around the case, including allegations about some kind of Kurdish connection, but nothing has ever been proved.

'Dissident group'

Mr Ocalan has alleged that the murder was carried out by a dissident Kurdish faction led by his ex-wife.

During his treason trial in Turkey in 1999, Mr Ocalan said the dissidents wanted to discredit his organisation, the PKK.

Other allegations have been made that the PKK itself was involved.

It is known that Kurdish groups in Sweden were under surveillance before Mr Palme's death amid suspicion that they were plotting a murder.

Some time after the killing, a number of Kurds were taken into custody, but they were released without charge.

Investigation criticised

Now the Swedish investigators want to hear from Mr Ocalan exactly what he says he knows.

Mr Ocalan's lawyers say the Turkish Ministry of Justice did not respond to their request to be present during the meeting.

Mr Ocalan has made many accusations since he was captured and he may have little proof about his theory on the Palme killing.

The Swedish police investigation has been heavily criticised and it appears to be no nearer to a solution.

A Swedish man, Christer Pettersson, was convicted of killing Palme in 1989, but he was later acquitted on appeal.