The recordings, MEE has learned, have given Turkey a detailed picture of the various operatives, teams and missions issued from Saudi Arabia, and the contents of the communications, the source said, will turn the screw on a Saudi leadership that has sought to insulate itself from the scandal.
According to the source, Turkey intends to drip feed the information gleaned from the communications to the media, as it has been doing ever since Khashoggi was brutally murdered by a team of 15 Saudis on October 2.
The Khashoggi-related conversations that Turkish intelligence intercepted began when the Washington Post columnist first came to his country’s consulate on September 28 in an attempt to get papers required to remarry.
The plan to kill Khashoggi, who was told to return to the consulate four days later, began to be hatched the moment he left the building, the source added.
“We know what happened in the consulate from the day Jamal stepped inside on Friday 28 September, to three days after the murder on 2 October,” the source told MEE.
“We know when the teams arrived, what they discussed with the consul-general, how they prepared themselves, how they were divided into groups, what mission each group had,” the source added.
Key conversations, the source said, were those between Consul-General Mohammad al-Otaibi and Saudi security attache Ahmed Abdullah al-Muzaini.
Muzaini has so far been spared much of the spotlight. It is unknown if he is one of at least 21 suspects detained in Saudi Arabia.
But Turkish newspaper Sabah, which is close to the government, has described Muzaini as the brains behind the plot.
On the day of Khashoggi’s murder, the conversations of one man are especially important.
MEE understands that Maher Abdulaziz Mutrib, the leader of the death squad sent to kill the journalist, made 19 calls to Riyadh on October 2.
Four of those, MEE has learned, were to Saoud al-Qahtani, top aide to Crown Prince Mohammad bin Salman (MbS).
According to the senior Turkish source, Qahtani was running the operation from the crown prince’s office.
The mission had been signed off by deputy intelligence chief Ahmed al-Assiri, but operations were largely in Qahtani’s hands, the source noted.
Both Assiri and Qahtani have been removed from their positions and are implicated in the Saudi prosecutor’s latest version of events, which was released on Thursday.
Puzzling to the Turkish source, however, is US intelligence’s knowledge of a phone conversation between Mutrib and Riyadh, where the team leader is apparently heard saying “tell your boss” following Khashoggi’s death.
Those words, which were apparently accompanied by “the deed is done”, were relayed to the New York Times by US intelligence officials.
MEE’s source, who is familiar with all the information Turkey has on the Khashoggi case, said the US’s intelligence expertise and spying technology may have allowed it to reveal more from audio shared between the two countries.
When CIA Chief Gina Haspel visited Turkey on October 23 for consultations over Khashoggi, she apparently arrived with a team of some 35 people.
Amongst them were experts in deciphering recordings, linguists, people familiar with the Saudi accent and people who could enhance audio, the source said.
Turkish intelligence officers were surprised when their US counterparts revealed the “boss” conversation, having missed that in the communications.
But according to the source, they told the Americans it was almost certainly Qahtani that Mutrib was talking to.
The Turks will listen to the tapes again, the source stated, and see what else was missed in the audio’s distortion.
Turkey’s understanding of Saudi movements and plans does not end on October 5, however.
According to the source, on October 15, the day after Turkish President Recep Tayyip Erdogan and Saudi Arabia’s King Salman spoke by phone, Riyadh dispatched two men to Istanbul tasked with covering up the murder.
“After the first phone call between Erdogan and King Salman, Erdogan accepted King Salman’s offer to establish a joint security investigation,” the source said, adding that “the Saudis immediately sent a 15-man team. Two of these were people whose only mission was to destroy the evidence”.
On Monday, Sabah reported that a chemist, Ahmad Abdulaziz Aljanobi, and toxicology expert, Khaled Yahya al-Zahrani, were among an 11-man “cover-up” team sent by Saudi Arabia to Istanbul on October 11.
However, MEE’s Turkish source understands that these two men were part of the second cover-up team, which only arrived after Erdogan and King Salman’s phone call. MEE could not independently verify this claim.
Turkey knew these men were arriving, the source noted, and were aware of the task set out for them.