Saudi Arabia claims a rogue “negotiation team” formed by one of Crown Prince Mohammad bin Salman’s top security officials, cheered on by his communications chief, and led by an intelligence official repeatedly pictured with him, killed journalist Jamal Khashoggi by injecting him with drugs during a bungled kidnap attempt.

But Saudi prosecutor Saud al-Mujeb insisted in an 18-minute press conference on Thursday that the crown prince himself had nothing to do with the operation that led to Khashoggi’s murder inside the Saudi consulate in Istanbul on 2 October.

Mr Mujeb also announced that his office was seeking the death penalty for five of 11 Saudi suspects already charged with the killing. Another 10 suspects remain in custody, state media reported.

Two other top officials, Crown Prince Mohammad’s former media adviser Saud al-Qahtani and former deputy head of intelligence General Ahmed al-Assiri, are under investigation for their role in the operation, he said. The US Treasury on Thursday slapped sanctions on Mr Qahtani and 16 Saudis over the murder.

In the latest version of the narrative presented by Saudis, the leader of a kidnapping team dispatched to Istanbul by Gen Assiri made an impromptu decision to kill Khashoggi inside his own nation’s consulate.

Saudi law forbids the naming of suspects. But those familiar with the case say the team leader was Maher Mutrib, a Saudi intelligence official once based in London who has frequently been pictured with Crown Prince Mohammad.

“After surveying the consulate, the head of the negotiation team concluded that it would not be possible to transfer the victim by force to the safe location in case the negotiations with him to return failed,” said the Saudi prosecutor, according to a report by the country’s official news agency. “The head of the negotiation team decided to murder the victim if the negotiations failed.”

Mevlut Cavusoglu, the foreign minister of Turkey, which has been pressing for full disclosure on the Khashoggi murder, described the account as “positive but insufficient”.

A Turkish source familiar with Ankara’s thinking on the matter described the prosecutor’s statement as “a great work of fiction”.

“He wants the world to believe that a group of goons just felt like killing the most prominent non-royal Saudi in the world.”

Jamal Khashoggi death: key figures Show all 7 1 /7 Jamal Khashoggi death: key figures Jamal Khashoggi death: key figures Jamal Khashoggi Washington Post journalist who was critical of the Saudi regime and the young Crown Prince Mohammed bin Salman, he was murdered on 2 October in the Saudi Arabian consulate in Istanbul AFP Jamal Khashoggi death: key figures Saudi Crown Prince Mohammed bin Salman Heir to the Saudi throne, Mohammed bin Salman has been implicated in the murder, with US officials claiming that he must have known of the plot AFP/Getty Jamal Khashoggi death: key figures 15 man hit squad Turkish police suspect these 15 men of being involved in the murder of Jamal Khashoggi, issued 10 October, 8 days after the journalist disappeared EPA Jamal Khashoggi death: key figures Saud al-Qahtani Aide to Crown Prince Mohammed bin Salman, Saud al-Qahtani is claimed to have ordered Khashoggi's murder Saud Al-Qahtani/Twitter Jamal Khashoggi death: key figures Maher Abdulaziz Mutreb A former diplomat who often travelled with the Crown Prince, Mutreb was initially claimed to be the leader of the hit squad and is pictured here entering the Saudi consulate on the day of the murder AP Jamal Khashoggi death: key figures Mustafa al-Madani First implicated in the 15 CCTV photos released by the Turkish police, al-Madani was later found to have been used as a body double for Khashoggi, leaving the Saudi consulate dressed in his clothes on the day the journalist was killed CNN Jamal Khashoggi death: key figures Salah bin Jamal Khashoggi (L) Son of the murdered journalist met with Crown Prince Mohammed bin Salman on 23 October EPA

Saudi Arabia has presented several evolving and contradictory versions of Khashoggi’s fate after he entered the consulate. The latest Saudi version continues to divert responsibility for the operation away from Crown Prince Mohammad, the brash 33-year-old heir to the throne who has tightened his grip on all aspects of Saudi security and economy.

Riyadh’s allies in western capitals eager to resume multibillion dollar energy and weapons deals and geopolitical machinations with Saudi Arabia have been pressuring its leadership to come up with a version of the killing that satisfies critics and experts who say it could not have been carried out without Crown Prince Mohammad’s blessing.

US Senator Lindsey Graham on Wednesday said that Crown Prince Mohammad “has been unstable and unreliable and I don’t see the situation getting fixed as long as he’s around”.

But the crown prince’s defenders have bristled at such suggestions, blaming western media and Turkey for jumping to conclusions.

“The Washington Post and the Turks (with their blatant political agenda) and others have prejudged the Khashoggi affair as ‘ordered by Mohammad bin Salman’ and anything less than that to them is a ‘coverup’,” Ali Shihabi, founder of a think tank close to Riyadh, wrote on Twitter, after a query by The Independent. “This despite the total absence of any hard evidence implicating him. They should either produce hard evidence or keep quiet.”

He noted that both Gen Assiri and Mr Qahtani had been demoted and are under investigation and a number of people have been arrested, comparing the Saudi handling of the case to the relative impunity enjoyed by western officials involved in airstrikes on civilians and detainee abuse.

“It’s not as if history is not full of examples of intelligence operatives exceeding their brief or screwing up an operation horribly,” he wrote. “Never has any of their top officials been implicated or serious punishment applied like this.”

The latest account is unlikely to mollify Saudi critics. For one thing, it fails to account for a phone call purportedly by a member of the Saudi kill team to Riyadh saying “tell your boss, the deed is done” shortly after the murder, as reported by The New York Times and The Washington Post this week.

It also fails to account for the role of Saudi consul general Mohammad al-Otaibi, who appears to have played a role in overseeing the murder and subsequent attempts to cover it up.

Saudi Arabia has also yet to account for leaked audio recordings which purportedly capture Khashoggi’s final moments and suggest he was strangled to death immediately after entering the consulate. Turkey’s president, Recep Tayyip Erdogan, has said his government has shared the intelligence with Saudi Arabia and other countries.

In his statement, Mr Mujeb beseeched Turkey to hand over all evidence it has collected to Riyadh. Ankara insists on trying any suspects in Turkey and has started to echo calls by human rights and press advocacy groups for an international investigation led by the United Nations.

According to Mr Mujeb, the operation was triggered a day after Khashoggi first visited the consulate on 28 September, with an order issued in Riyadh by Gen Assiri to bring the journalist back to Saudi Arabia by means of “persuasion” or “force”.

The leader of the mission is said to have formed a 15-man team, divided into three groups: negotiation, intelligence, and logistics. Mr Mutrib allegedly added a forensics expert to the team to help cover its tracks during the kidnapping attempt, not to get rid of the body, the prosecutor said.

The 15 men were led to believe they were grappling with a dire national security threat, not subduing a middle-aged writer. According to the prosecutor, Mr Qahtani told the team Khashoggi’s return would represent “a significant achievement” and “expressed his belief that the victim was co-opted by organisations and states hostile to Saudi”.

The Saudi team disabled the consulate’s security cameras ahead of Khashoggi’s scheduled 2 October arrival, the prosecutor said.

After an “altercation” with Khashoggi, the Saudi operatives held him down, injected him with deadly dosage of an undisclosed drug, dismembered his body, and then handed off his remains to an unnamed and unidentified “collaborator”, the Saudi prosecution alleged.

The Turkish source mocked the scenario. “The Saudi prosecutor repackaged the ‘fist fight’ claim and included it in his statement hoping nobody would notice,” they said, noting that officials in Riyadh have gone back and forth on the existence of the local collaborator. “They have been flip-flopping on this issue for weeks,” he said. “All they have to do is tell Turkey what the local collaborator looks like.”

Mr Mujeb said authorities had identified the suspect who handed the body off to the local collaborator, drawn up a sketch of the local collaborator, and identified the pudgy middle-aged team member who donned Khashoggi’s clothes and wandered around the city in an attempt to fool Turkish surveillance.

After killing Khashoggi, the team members then falsely told Gen Assiri that the journalist had exited the consulate, Mr Mujeb said.

Yasin Aktay, an adviser to Turkey’s ruling party and a friend of Khashoggi, derided the Saudi account. “It is obvious that there is no intention to deeply investigate the incident,” he said in an interview with Turkish television.