ANKARA (BLOOMBERG) - Saudi Arabia's Crown Prince Mohammed Bin Salman remains "the chief suspect" in the killing of Washington Post columnist Jamal Khashoggi, an adviser to Turkish President Recep Tayyip Erdogan said after meeting the United Nations representative probing the murder.

Turkey will allow UN special rapporteur Agnes Callamard to listen to voice recordings of Mr Khashoggi's last moments, according to Mr Yasin Aktay, an Erdogan aide at the ruling AK Party.

Ms Callamard is in Turkey to examine the circumstances surrounding the murder of Mr Khashoggi, who entered the kingdom's consulate in Istanbul on Oct 2 but never left.

The top diplomatic privileges awarded to the team of assassins that killed the journalist show that the crown prince is the "No. 1 suspect" in the murder, Mr Aktay told Bloomberg on Friday (Feb 1).

Mr Aktay has played a key role in efforts to maintain pressure on Saudi officials over the fate of Mr Khashoggi, a Saudi insider-turned-critic who was killed after criticising the crown prince for his style of governance.

Riyadh eventually acknowledged his death at the hands of Saudi officials, but has failed to produce his body. The kingdom denies the crown prince played any role.

The investigation in Saudi Arabia isn't transparent and the real culprits are yet to be held to account, Turkey says.