ANKARA:- It took seven minutes for Jamal Khashoggi to die, a Turkish source who has listened in full to an audio recording of the Saudi journalist's last moments told Middle East Eye.

Khashoggi was dragged from the consul-general's office at the Saudi consulate in Istanbulinfo-icon and onto the table of his study next door, the Turkish source said.

Horrendous screams were then heard by a witness downstairs, the source said.

"The consul himself was taken out of the room. There was no attempt to interrogate him. They had come to kill him," the source told MEE.

The screaming stopped when Khashoggi - who was last seen entering the Saudi consulate on 2 October - was injected with an as yet unknown substance.

Salah Muhammad al-Tubaigy, who has been identified as the head of forensic evidence in the Saudi general security department, was one of the 15-member squad who arrived in Ankara earlier that day on a private jet.

Tubaigy began to cut Khashoggi's body up on a table in the study while he was still alive, the Turkish source said.

The killing took seven minutes, the source said.

As he started to dismember the body, Tubaigy put on earphones and listened to musicinfo-icon. He advised other members of the squad to do the same.

"When I do this job, I listen to music. You should do [that] too," Tubaigy was recorded as saying, the source told MEE.

A three-minute version of the audio tape has been given to Turkish newspaper Sabah, but they have yet to release it.

A Turkish source told the New York Times that Tubaigy was equipped with a bone saw. He is listed as the president of the Saudi Fellowship of Forensic Pathology and a member of the Saudi Association for Forensic Pathology.

In 2014, London-based Saudi newspaper Asharaq al-Awsat interviewed Tubaigy about a mobile clinic that allows coroners to perform autopsies in seven minutes to determine the cause of death of Hajjinfo-icon pilgrims.

The newspaper reported that the mobile clinic was partly designed by Tubaigy and could be used in "security cases that requires pathologist intervention to perform an autopsy or examine a body at the place of a crime".

These are the first details to emerge of the Saudi journalist's killing. Khashoggi was last seen entering the Saudi consulate in Istanbul on 2 October to retrieve paperwork.

To date, Saudi officials have strongly denied any involvement in his disappearance and say that he left the consulate soon after arriving. However, they have not presented any evidence to corroborate their claim and say that video cameras at the consulate were not recording at the time.

Calls for credible investigation grow louder

On Tuesday, both USinfo-icon President Donald Trumpinfo-icon and Mike Pompeo, his secretary of state, came out in support of Saudi officials's denials they know anything about what happened to Khashoggi. 

Trump tweeted that he spoke to Saudi Crown Prince Mohammed bin Salman, who "totally denied any knowledge of what took place" in Istanbul. Trump said MBS told him "that he has already started, and will rapidly expand, a full and complete investigation into this matter".

On Monday, CNN reported that Saudi Arabiainfo-icon was preparing to release a report that would blame Khashoggi's death on a botched interrogation.

That would be a sharp reversal of earlier statements in which Saudi officials said they had nothing to do with the journalist's disappearance and said he left the Saudi consulate minutes after he first arrived on 2 October.

Khashoggi, a prominent journalist and columnist for the Washington Post, had been living in self-imposed exile in the US capital when he disappeared.

On Tuesday, Washington Post publisher and CEO Fred Ryan called for a "full and honest explanation" of Khashoggi's disappearance.

"The Saudi government can no longer remain silent, and it is essential that our own government and others push harder for the truth," Ryan said in a statement. "Until we have a full account and full accountability, it cannot be businessinfo-icon as usual with the Saudi government."

The United Nationsinfo-icon human rightsinfo-icon chief also called for diplomatic immunity to be lifted for officials who might be involved in Khashoggi's disappearance.

Due to the seriousness of the case, the immunity generally accorded to diplomats "should be waived immediately", Michelle Bachelet said.