Saudi Arabia has said journalist Jamal Khashoggi was murdered in a “rogue operation” – after weeks of giving conflicting accounts.

Foreign minister Adel al-Jubeir told Fox News that the killing was a “tremendous mistake” but denied powerful Crown Prince Mohammed bin Salman ordered the death of the Washington Post columnist.

“We are determined to find out all the facts. And we are determined to punish those who are responsible for his murder,” he said.

He added: “The individuals who did this did this outside the scope of their authority. There obviously was a tremendous mistake made, and what compounded the mistake was the attempt to try and cover up.

“Even the senior leadership of our intelligence service was not aware of this.”

Khashoggi was last seen entering the Saudi consulate in Istanbul, Turkey on October 2.

He was collecting documents which would allow him to marry his fiancée, Hatice Cengiz, who was waiting outside.

The official added that Saudi Arabia does not know where the body is.

It comes as an image taken from CCTV footage shows Maher Abdulaziz Mutreb, a member of MBS’ entourage, at the consulate before Khashoggi’s arrival.

A forensics and post-mortem expert was also on hand for the journalist’s arrival – a finding which has not been explained by Saudi Arabia.

Saudi Arabia at first denied Khashoggi had disappeared, saying he left the building alive shortly after – despite no CCTV showing his exit.

On Friday, the public prosecutor claimed he had died in a “fist fight” – the first time the kingdom admitted he was dead. The Saudis say 18 individuals have been detained for the murder amid international outcry.

Turkish officials say they have audio evidence that the 59-year-old was murdered.

According to the state-run Saudi Press Agency, the Crown Prince and King Salman called Khashoggi’s son to express condolences.

President Recep Tayyip Erdogan says he will reveal the “naked truth” about the case in a speech in Parliament on Tuesday.

The UK, France and Germany issued a joint statement demanding a full explanation of the death, saying: “Nothing can justify this killing and we condemn it in the strongest possible terms”.

US President Donald Trump has said he would “love” if the crown prince was not responsible, and criticised the kingdom for its “deception and lies”.