SAUDI Arabia has admitted for the first time that the killing of journalist Jamal Khashoggi was "murder" describing it as a "tremendous mistake" and part of a "rogue operation".

In a new account of the act that sparked an international outcry, Saudi Arabia foreign minister Adel al-Jubeir pledged that his government would punish those responsible and denied Crown Prince Mohammed bin Salman had ordered it.

Mr Khashoggi, a prominent critic of the Saudi government, was last seen entering the Saudi consulate in Istanbul, Turkey.

"The individuals who did this did this outside the scope of their authority," Mr al-Jubeir told Fox News. "There obviously was a tremendous mistake made, and what compounded the mistake was the attempt to try to cover up. That is unacceptable in any government."

"We are determined to uncover every stone. We are determined to find out all the facts. And we are determined to punish those who are responsible for this murder," he said.

The Herald:

“This was an operation where individuals ended up exceeding the responsibilities they had and they made the mistake when they killed Jamal Khashoggi in the consulate and they tried to cover up for it.”

He said such a cover-up was “unacceptable in any government” and the investigation into Mr Khashoggi’s death would be the start of a long process.

The Saudis, under intense pressure to explain what happened to Mr Khashoggi, a former editor-in-chief of the Al-Arab News Channel, have offered conflicting accounts.

They initially said he had left the consulate on October 2 - but on Friday admitted for the first time he was dead, saying he had been killed in a fight and that 18 Saudi nationals had been arrested.

Turkish officials believe Mr Khashoggi was murdered by a team of Saudi agents inside the building and say they have evidence to prove it.

Mr al-Jubeir said that crown prince was not aware of the operation beforehand. "Even the senior leadership over intelligence service was not aware of this," he said.

He said Saudi Arabia did not know what happened to Mr Khashoggi's body and had not heard any audio from inside the consulate.

He cautioned against reaching quick conclusions adding: "These things take time."

And he offered his condolences to the Khashoggi family, saying: “We feel their pain. And I wish this didn't happen and I wish that this could've been avoided. Unfortunately, a huge and grave mistake was made. And I assure them, that those responsible will be held accountable for this.”

Leaked CCTV footage emerged on Monday that appeared to show a "body double" wearing Mr Khashoggi's clothes just hours after he was killed.

The video, broadcast by CNN, shows the man strolling out of the Saudi consulate in Istanbul where the journalist was killed.

CNN cited a Turkish official describing the man as a "body double" and a member of group sent to Istanbul to target the 59-year-old writer.

CNN says the man walked out of the consulate via its back exit with an accomplice, then took a taxi to Istanbul's Sultan Ahmed Mosque, where he went into a bathroom and changed back out of the clothes and left.

Turkish media reported that a 15-person Saudi team flew to Istanbul on October 2 knowing Mr Khashoggi would arrive for a document he needed to get married.

Once he was inside the diplomatic mission, it is alleged the group questioned Mr Khashoggi, cut off his fingers, killed and dismembered him.

The Herald: Turkey’s President Erdogan warns opposition not to question referendum result

Turkish President Recep Tayyip Erdogan has said that details of Mr Khashoggi's killing "will be revealed in all its nakedness" in a speech in parliament on Tuesday.

Theresa May condemned the killing, telling MPs: "I am sure the whole House will join me in condemning the killing of Jamal Khashoggi in the strongest possible terms... we must get to the truth of what happened."

On Sunday, the UK, French and German foreign ministers released a joint statement on Khashoggi, noting Saudi Arabia's preliminary findings but calling for an "urgent need for clarification" on what exactly happened after he entered the consulate on October 2.

"Nothing can justify this killing," the statement said.