Family members of Saudi journalist Jamal Khashoggi on Monday called for an independent investigation into his disappearance, Reuters reported. Khashoggi was last seen on October 2 entering the Saudi consulate in Istanbul, Turkey.

“We are sadly and anxiously following the conflicting news regarding the fate of our father after losing contact with him two weeks ago,” said a statement from the family. “The strong moral and legal responsibility which our father instilled in us obliges us to call for the establishment of an independent and impartial international commission to inquire into the circumstances of his death.”

Khashoggi, a vocal critic of the Saudi regime, had been living in self-imposed exile in the United States since 2017.

Turkish Police personnel conducted an overnight search of the Saudi consulate in Istanbul, spending more than nine hours in the building. Four forensic vehicles extracted soil samples as well as a metal door from the garden at the consulate. The crime scene investigation team, comprising at least 10 people and a police dog, left on Tuesday morning, reported Reuters.

On Monday, US President Donald Trump said he was sending Secretary of State Mike Pompeo to meet Saudi Arabia’s King Salman to discuss Khashoggi’s disappearance. Pompeo will also visit Turkey, the BBC reported. Salman has denied any knowledge and ordered an internal inquiry into the incident.

Saudi Arabia on Sunday rejected any threats or attempts to undermine the kingdom over the missing journalist and warned of retaliation if there was any punitive action against it.

Turkish officials suspect a 15-member team “came from Saudi Arabia” to murder the dissident. Last week, the kingdom had allowed Turkey to search its consulate in Istanbul.