A team of Turkish police investigating the disappearance of Saudi journalist Jamal Khashoggi, who vanished after entering the Saudi consulate in Istanbul two weeks ago, spent more than nine hours in the building, a Reuters witness said.

A crime scene investigation team of around 10 people left the consulate after completing a search early on Tuesday, the witness said, the Reuters reported.

President Donald Trump suggested Monday that ‘rogue killers’ could be behind the disappearance of Saudi journalist Jamal Khashoggi, after a phone call with Saudi Arabia’s King Salman about the case, the CNN reported.

Trump told White House reporters that Salman offered him a ‘flat denial’ in relation to the disappearance of Khashoggi, a columnist for The Washington Post who was last seen in public when he entered the Saudi consulate in Istanbul in Turkey on October 2.

Later Monday, the Saudis were preparing to admit that Khashoggi died during an interrogation that went wrong, one that was intended to lead to his abduction from Turkey, according to two sources.

Secretary of State Mike Pompeo left Washington for Riyadh at around midday to meet with the Saudi King on Trump’s orders.

Previously, Saudi authorities had maintained that Khashoggi left the consulate the same afternoon of his visit, but have provided no evidence to support the claim. Khashoggi’s fiancée, Hatice Cengiz, who was waiting outside the consulate, says she did not see him re-emerge.

Khashoggi, a US resident, Washington Post columnist and leading critic of the powerful Saudi crown prince, Mohammed bin Salman, vanished after entering the consulate to get marriage documents. Turkish officials say they believe he was murdered there and his body removed.

Four forensic vehicles arrived outside the consulate and took away soil samples as well as a metal door from the garden, the Reuters witness said. A police dog was part of the search team.

A Turkish diplomatic source had earlier said that a joint Turkish-Saudi team would search the consulate - the last place Khashoggi was seen before he vanished on Oct. 2.