Saudi Arabia’s Crown Prince Mohammed bin Salman (MBS) has admitted 'all responsibility' over Khashoggi murder but denies prior knowledge of execution.

According to a Public Broadcasting Service (PBS) documentary to be broadcast next week, Prince Mohammed bin Salman, the kingdom's de facto ruler since 2017, said he is taking responsibility “because it happened under my watch.”

"It happened under my watch. I take all the responsibility, because it happened under my watch," he told PBS's Martin Smith, according to a preview of the documentary, "The Crown Prince of Saudi Arabia," set to air ‪on October 1, ahead of the one-year anniversary of Khashoggi's death, which took place at the exact date of October 2, 2018, according to Daily Sabah. 

However he quickly stepped away from admitting full responsibility, saying he couldn't have known about the killing because of the sheer number of government employees in the country.

"We have 20 million people. We have three million government employees," he said when questioned on why he didn’t know about the murder.

Prince Mohammed has come under huge international pressure after the US-based writer was killed and dismembered in the Saudi consulate in Istanbul.

Khashoggi's body has not been recovered,

Riyadh has repeatedly denied that Prince Mohammed was behind the murder of Khashoggi - a one-time royal family adviser - who was killed in what Saudi authorities have described as a rogue operation.

However a comprehensive report by a UN human rights expert Agnes Callamard, who conducted an independent probe, said there was “credible evidence” linking the crown prince to the murder and an attempted cover up.

According to the report, a squad of 15 officials, including a forensic doctor and professor of criminal evidence, many of whom had close ties to bin Salman, were flown out on a diplomatic plane the day before Khashoggi was known to be coming into the consulate.

The CIA has also reportedly said the killing was likely ordered by Prince Mohammed.

The documentary is one of two interviews airing in the coming days that mark the first time bin Salman has spoken publicly about the Khashoggi scandal.

The Guardian says Khashoggi, a critic of the crown prince, went missing after entering the consulate to obtain documents for his upcoming marriage. Days later, Turkish officials said they believed he had been killed in the building, an allegation that Saudi Arabia initially strenuously denied.