The UK said on Wednesday that it would revoke visas of all suspects linked to the murder of the Saudi writer.
He was last seen entering the Saudi consulate in Istanbul on October the second.
The Turkish leader has called on Riyadh to prosecute those behind the journalist's murder in Istanbul.
It later dropped that account for a new one, saying it had detained 18 people for what it described as an accidental killing during a "fistfight".
"They had a very bad original concept".
Saudi Crown Prince Mohammed bin Salman is now under heavy scrutiny after the Khashoggi case.
Saudi Crown Prince Mohammed bin Salman on Wednesday joked about Lebanese Prime Minister Saad al-Hariri's detention in the kingdom previous year, saying he was free to leave after attending an global investment conference in Riyadh. "And it is painful, heinous to every human being in the world", Mohammed bin Salman said during an address at the Future Investment Initiative Forum in Riyadh. "We will continue to explore additional measures to hold those responsible accountable".
It also contradicts many observers who believe the complex scheme that led to Khashoggi's death could not have occurred without the knowledge of the crown prince, who controls all major levers of power in the kingdom with the blessing of his father, King Salman.
USA lawmakers have increased their pressure on the Trump administration, accusing the crown prince of ordering the killing. The kingdom first denied any involvement in the disappearance, but amid mounting worldwide pressure, acknowledged that he had been killed at the consulate in a rogue operation.