CIA officials are certain that Saudi Crown Prince Mohammed bin Salman ordered last month’s assassination of journalist Jamal Khashoggi in Istanbul, despite the Saudi government’s claims to the contrary, according to The Washington Post.

Khashoggi, a U.S. resident who was a contributor to The Washington Post, was last seen entering the Saudi consulate in Istanbul on Oct. 2. The Saudi writer is believed to have been killed soon after entering the building. It is believed his body was dismembered and disposed of.

The CIA reportedly examined multiple sources of intelligence, including a phone call to Khashoggi from the prince’s brother Khalid bin Salman, the Saudi ambassador to the United States.

Sources said Khalid told Khashoggi that he should go to the Saudi consulate in Istanbul to retrieve some documents, while assuring him that he would be safe.

Although it’s not clear if Khalid knew that Khashoggi would be killed, he did make the call at his brother’s direction, and it was intercepted by U.S. intelligence.

Khalid bin Salman denied the allegation via Twitter soon after the Post published its article.

As we told the Washington Post the last contact I had with Mr. Khashoggi was via text on Oct 26 2017. I never talked to him by phone and certainly never suggested he go to Turkey for any reason. I ask the US government to release any information regarding this claim. — Khalid bin Salman خالد بن سلمان (@kbsalsaud) November 16, 2018

He elaborated a short time later.

Unfortunately the @washingtonpost did not print our full response. This is a serious accusation and should not be left to anonymous sources. Our full response was the following: pic.twitter.com/vo1JcNAswx — Khalid bin Salman خالد بن سلمان (@kbsalsaud) November 17, 2018

A CIA official told The Wall Street Journal on Friday that the agency came to its conclusion the Crown Prince ordered the killing not on “smoking gun” evidence but rather on “an understanding of how Saudi Arabia works.”

“This would not and could not have happened” without Mohammed bin Salman’s involvement, the official said.

On Thursday, Saudi Arabia’s public prosecutor announced it would seek the death penalty for five of 11 suspects, even though Turkish leader Recep Tayyip Erdoğan said the killing was ordered at the “highest levels” of the Saudi government.

Khashoggi was once close to the Saudi royal family, but had grown increasingly critical of human rights abuses in the kingdom and was living in Washington, D.C. Although the kingdom considered him a “dissident,” he never wanted the label, according to a tweet posted last month by fellow Washington Post writer Karen Attiah.

One thing I keep wanting to stress: Jamal Khashoggi (@Jkhashoggi) would often tell me he never wanted to be labeled a ‘dissident’ or an opposition figure living in exile. He really just wanted to write freely and to be a journalist. #JamalKhashoggi #JamalKhashoggi — Karen Attiah (@KarenAttiah) October 8, 2018