Five Saudi officials are facing the death penalty after being accused of murdering journalist Jamal Khashoggi.

Shalaan al-Shalaan, the kingdom's deputy public prosecutor, revealed on Thursday that 21 people are in custody over the killing and charges have been brought against 11 of them.

Al-Shalaan requested the death penalty for five who 'are charged with ordering and committing the crime and for the appropriate sentences for the other indicted individuals'.

But he exonerated Saudi's de-facto ruler Mohammed bin Salman by laying ultimate blame for Khashoggi's killing at the feet of two lesser officials.

Executions in Saudi Arabia are usually carried out publicly by beheading with a sword.

Saudi Arabia will seek the death penalty against five men it accuses of carrying out the murder of journalist Jamal Khashoggi in Istanbul on October 2

Shalaan al-Shalaan, the deputy public prosecutor of Saudi Arabia, revealed that 21 people are in custody over the killing and 11 of them have been charged

Shalaan said the highest-level official implicated in Khashoggi's killing is former deputy intelligence chief Ahmed al-Assiri, who gave the order for him to be repatriated to Saudi Arabia from Turkey, where he was living in exile.

He added that it was 'the head of the negotiating team' dispatched to seize Khashoggi who then gave the order to kill him, without naming the man.

Shalaan denied that Salman had any knowledge of the killing. The Crown Prince has blamed it on 'rogue elements' of the Saudi state.

That was a claim backed by foreign minister Adel al-Jubeir who said bin Salman has 'absolutely nothing to do' with the death.

'Sometimes mistakes happen... sometimes people exceed their authority,' he said before adding Saudi was taking steps 'to make sure this doesn't happen again.'

Crown Prince Mohammed bin Salman has not been implicated in the killing after blame was laid at the feet of two lesser officials

Meanwhile Turkey's public prosecutor said news of the charges was 'positive but insufficient'.

Turkey has previously said it believes officials at the very top level of Saudi's ruling family are to blame for the murder, but stopped short of accusing bin Salman.

Saudi Arabia added that it believes Khashoggi was given a lethal injection inside the country's consulate in Istanbul on October 2.

Top intelligence officer General Ahmed al-Assiri was fired in connection with the death, and is now facing charges

His body was then dismembered and taken out of the building, Shalaan said, though admitted the kingdom does not not know where the remains are now.

Investigations are ongoing to find the remains, the prosecutor insisted.

Hatice Cengiz, Khashoggi's fiancee who was with him at the consulate the day he died to retrieve documents allowing them to marry, has demanded the kingdom hand back his remains for a proper burial.

After repeated denials, Saudi Arabia finally admitted in mid-October that Khashoggi had been murdered at the compound, but blamed it on a 'rogue' operation.

The prosecutor has requested the death penalty for the five who 'are charged with ordering and committing the crime and for the appropriate sentences for the other indicted individuals,' an official statement published by state news agency SPA said.

It said a total of 21 individuals were in custody in connection with the killing, 11 of whom have been indicted with investigations to continue into the others.

Turkey on Wednesday called for an international investigation into the murder.

Ankara has already shared voice recordings linked to the murder with a number of countries including Saudi Arabia, the United States and its Western allies.

Two members of the Saudi team which is said to have killed Jamal Khashoggi going through the scanners at Ataturk airport on October 2 where the contents of their bags were pictured

X-ray images taken in Istanbul's Ataturk airport of the hit squad's luggage showed syringes and radios. Jamal Khashoggi was killed on October 2 inside the Saudi consulate in Istanbul on the same day the 15-man squad flew in

Another image purportedly showing one of the hit squad member's bags shows a pair of scissors

Other scans also showed what appeared to be a pair of staple-guns and a taser in the luggage

Khashoggi's killing has plunged the world's top oil exporter into its worst diplomatic crisis since the September 11, 2001 terrorist attacks on the United States, in which most of the hijackers were identified as Saudi nationals.

After first insisting Khashoggi left the consulate unharmed, Saudi authorities said he was killed in an argument that degenerated into a brawl before finally accepting what Turkey had said virtually from the start - that he was killed in a premeditated hit.

Turkish President Recep Tayyip Erdogan has said the order to murder Khashoggi came from 'the highest levels' of the Saudi government.

The global fallout over the murder has tainted the image of 33-year-old Prince Mohammed - the de facto ruler and heir apparent - despite persistent Saudi denials that he was involved.

Khashoggi's murder has also led to increased scrutiny of Saudi Arabia's role in the Yemen war, which has pushed the impoverished country to the brink of famine.

The journalist went into self-imposed exile in the United States in 2017 after falling out with Prince Mohammed.