'World is watching' Khashoggi investigation, Kushner warns Saudi prince

US President Donald Trump's senior adviser and son-in-law has warned the Saudi crown prince that "the world is watching" the kingdom amid the controversy over the murder of Jamal Kashoggi.

Jared Kushner, who has close ties to Mohammed bin Salman, told CNN on Monday that he has urged the de-facto Saudi ruler to carry out a "transparent" investigation into the killing.

"The world is watching. Make sure you're transparent, take this very seriously," Kushner said that he told MbS.

"This is a very serious accusation, a very serious situation,"

Kushner, however, refused to comment on whether he believed the official Saudi narrative of Kashoggi's killing.

"We have our eyes wide-open and the president is focused on what is good for America," he added.

After a fortnight of denials, Saudi authorities admitted on Saturday that Khashoggi, a prominent critic of MbS, was killed after entering the consulate in Turkey on October 2.

Riyadh is now facing a growing chorus of incredulity over its belated explanation that Khashoggi died in a "brawl".

The Wall Street Journal reported this week that MbS called Jared Kushner eight days after Khashoggi went missing to ask him why there was such a strong international outrage over the incident.

The son of King Salman has developed close ties with the Trump White House, and especially with Kushner, since becoming crown prince last year.

Last year, Kushner paid a secret visit to Saudi Arabia to discuss his still-secret Israeli-Palestinian peace proposal he has been working on for months.