A little over a week ago, a prominent Saudi journalist walked into the consulate general in Istanbul, intending to get paperwork that would allow him to marry his Turkish fiancée. She hasn't seen him since.

Since then, officials and journalists have scrambled to piece together the story of what happened to Jamal Khashoggi, a former Saudi royal insider who became a critic of the regime of Crown Prince Mohammed bin Salman.

Turkish authorities have privately said they believe Khashoggi was killed inside the consulate, a startling allegation that is firmly denied by the Saudis.

Closed-circuit television footage, flight trackers, intercepted communications and even rumours of a bone saw have served as pieces of a puzzle that has spurred a diplomatic outcry.

In the latest developments on Wednesday, Turkish security officials concluded that the “highest levels of the royal court” in Saudi Arabia ordered the assassination of Khashoggi, according to a senior official cited by The New York Times.

Turkish officials have said that a 15-person team flew from Saudi Arabia into Istanbul on the day Khashoggi entered the consulate, and they have provided information about two private planes that, they say, were involved in the transit of these Saudis.

Aviation data analyzed by CNN backs up evidence of the planes’ arrival in Istanbul. The official quoted by the New York Times described the operation as “quick and complex,” and that Khashoggi was killed within two hours of his arrival at the consulate.

The agents “dismembered his body with a bone saw they brought for the purpose,” the official told The New York Times. “It's like ‘Pulp Fiction,'” he added.

About the only thing that is known for sure about Khashoggi's fate is that he was last seen at 1:14 p.m. local time last Tuesday as he entered the consulate.

His disappearance has prompted calls for investigations from around the world.

The kingdom's staunchest Western allies, including the United States, where Khashoggi had applied for permanent residency, have urged Saudi Arabia to come clean. Trump said Wednesday that he's been in touch with the “highest levels” of the Saudi government about Khashoggi's case and expressed concerns about his possible murder.

He said his administration was pressing the Saudi government to reveal more about the incident.

“We're demanding everything. We want to see what's going on here. It's a bad situation,” Trump said in the Oval Office.

But he stopped short of saying whether he believed the Saudis have knowledge about his whereabouts or may have played a role in his disappearance, stating that not enough was known to make a determination.

Khashoggi's fiancée, Hatice Cengiz, told CNN that although she is afraid that media reports of his death could be true, she wants to wait for a “final result” and still thinks “anything” could have happened to him.