On the same day of Khashoggi's disappearance, 15 other Saudis, including several officials, arrived in Istanbul on two planes and visited the consulate while he was still inside, according to Turkish police sources. Two senior Saudi officials have been fired over the incident.
The public prosecutor said 18 people, all Saudi nationals, have been detained in connection to the probe.
The incident had threatened to create a diplomatic crisis with the USA, which sees its alliance with Riyadh as the cornerstone of its Middle East policy, and Turkey, which has tenuous ties with Saudi Arabia.
The reporting that Castro is referring to is an article from the British tabloid The Daily Mail published this past April that claimed the crown prince had boasted about some key intelligence he had received from Kushner about enemies within his kingdom who were plotting against him. According to the king's order, the committee is to report back to him within a month.
Senator Lindsey Graham, a close Trump ally who has nonetheless been outspoken about Khashoggi, doubted the credibility of the Saudi authorities, which insisted for weeks that he left the consulate. Saudi Arabia had claimed ignorance of the incident before making this statement.
He also said the arrests in Saudi Arabia were a "big first step" and that he would prefer not to jeopardise America's $US110 billion arms deal with the country. He did not disclose the whereabouts of his body.
It is the first time Saudi Arabia has admitted the journalist is dead.
The Saudi king also ordered the setting up of ministerial committee under the chairmanship of the crown prince, widely known as MBS, to restructure the kingdom's intelligence agency and "define its powers accurately".
It comes as the Saudi government comes under increasing global pressure over the disappearance of Jamal Khashoggi - a journalist who was allegedly killed after entering the country's consulate in Turkey.
The president is trying to defend the Saudi regime and specifically Mohammed bin Salman.
However the mission is said to be led by his son Crown Prince Mohammed bin Salman, who was suspected of being behind Khashoggi's disappearance in some versions of stories alleging what happened to the Washington Post writer.
"To say that I am skeptical of the new Saudi narrative about Khashoggi is an understatement", Republican Senator Lindsey Graham of SC said on Twitter.
Fellow Republican Congressman Mike Coffman called on Mr Trump to recall the USA ambassador to the kingdom, "pending further consultation with congress".
In a statement Friday night, White House press secretary Sarah Huckabee Sanders says the USA will closely follow worldwide investigations into Khashoggi's death and will advocate for justice that is "timely, transparent and in accordance with all due process".
Oct 13: A Turkish newspaper reports that Mr Khashoggi's torture and killing were recorded on his Apple Watch, which had transmitted the data to an iPhone he had given to his fiancee before entering the consulate.
Khashoggi, who has been missing since the beginning of October, went to the consulate to complete paperwork so he could marry his Turkish fiancée, and was never seen leaving. "The results of the preliminary investigations also revealed that the discussions [between Khashoggi and the suspects] did not go as required and developed in a negative way [and] led to a fight and a quarrel [and] the brawl aggravated to lead to his death and their attempt to hide and cover what happened".