The order for the murder of Washington Post journalist Jamal Khashoggi inside the Saudi consulate in Turkey exactly one month ago came from the “highest level” inside the Saudi government, according to Turkey’s president.

In an opinion piece published in the Washington Post on Saturday (Friday local time), Recep Tayyip Erdogan called on the Saudi government to reveal the identities of the “puppet masters” behind Khashoggi’s brutal death.

“The killing of Khashoggi is inexplicable,” he wrote.

“Had this atrocity taken place in the United States or elsewhere, authorities in those countries would have gotten to the bottom of what happened.”

Mr Erdogan said Turkey’s friendship with Riyadh did not mean that his country could turn a blind eye to the “premeditated murder that unfolded in front of our very eyes”, adding that he didn’t believe that King Mohammed bin Salman ordered the killing.

“I do not believe for a second that King Salman, the custodian of the holy mosques, ordered the hit on Khashoggi.

“We know the perpetrators are among the 18 suspects detained in Saudi Arabia. We also know those individuals came to carry out their orders: Kill Khashoggi and leave. Finally, we know the order to kill Khashoggi came from the highest levels of the Saudi government.

“Some seem to hope this ‘problem’ will go away in time. But we will keep asking those questions, which are crucial to the criminal investigation in Turkey, but also to Khashoggi’s family and loved ones.

“A month after his killing, we still do not know where his body is. At the very least, he deserves a proper burial in line with Islamic customs. We owe it to his family and friends,” Mr Erdogan wrote.

A video recording of a speech by Khashoggi’s fiancée Hatice Cengiz, played during a memorial service for him in Washington, DC. Photo: Getty

Earlier, Khashoggi’s Turkish fiancée Hatice Cengiz made an appeal to US President Donald Trump in a video message to mark the one-month anniversary of his death on October 2, when he entered the consulate to organise papers for his upcoming wedding.

Ms Cengiz waited several hours for her fiancé to return before alerting authorities to his disappearance.

“I would like him [Mr Trump] to support Turkey’s efforts in trying to bring light to this situation and to discover the whereabouts of his body,” Ms Cengiz said.

Mr Trump has condemned Khashoggi’s killing in strong terms, but has also defended US arms sales to Saudi Arabia, which is the biggest foreign customer for American weaponry.

Meanwhile, Istanbul’s chief prosecutor announced on Wednesday that Khashoggi was strangled immediately after he entered and that his body was dismembered and removed from the consulate.

Turkish presidential adviser Yasin Aktay was quoted by Turkish newspaper Hurriyet on Friday saying that after being dismembered, Khashoggi’s body was dissolved using a chemical substance.

Turkey is seeking the extradition of 18 suspects so they can be put on trial in Turkey including 15 members of an alleged Saudi “hit squad” that Turkey says was sent to Istanbul to kill Khashoggi, who lived in exile in the United States and had written critically of Saudi Arabia’s Crown Prince Mohammed bin Salman.

Some of those implicated in the killing are close to the prince, whose condemnation of the murder has failed to ease suspicions that he was involved.

Saudi Arabia has changed its narrative about Khashoggi’s killing several times, but has recently acknowledged that Turkish evidence shows it was premeditated.

Celebrities, actors write to the UN for investigation

International condemnation of Khashoggi’s murder has gained momentum in recent days, with more than 100 celebrities, writers and actors adding their names on a letter addressed to the UN urging secretary general António Guterres to initiate an independent investigation.

“If true, the murder of a journalist inside a diplomatic facility would constitute nothing less than an act of state terror intended to intimidate journalists, dissidents, and exiled critics the world over,” the letter dated November 2 read, and signed by 100 people including Hollywood actress Meryl Streep, award-winning veteran Washington Post investigative journalist Bob Woodward and author J K Rowling.

“The violent murder of a prominent journalist and commentator on foreign soil is a grave violation of human rights and a disturbing escalation of the crackdown on dissent in Saudi Arabia, whose government in recent years has jailed numerous writers, journalists, human rights advocates, and lawyers in a sweeping assault on free expression and association.

“We therefore respectfully call on you to immediately authorise an independent, international investigation into the murder of Jamal Khashoggi that would lay the groundwork for identifying and holding accountable the perpetrators of this grievous crime,” the letter concludes.

-with agencies