"Unfortunately, a huge and grave mistake was made and I assure them that those responsible will be held accountable for this".
A Saudi friend of Khashoggi told The Associated Press that Khashoggi's son, Salah, has been under a travel ban since a year ago as a result of his father's criticism of the kingdom.
"Even the senior leadership over intelligence service was not aware of this", al-Jubeir said. He adds Saudi officials do not know the whereabouts of Khashoggi's remains.
A bipartisan group of US lawmakers is accusing the crown prince of directing the operation. "So let's hope that the world would deal with the political crisis, including the one with a Saudi citizen in Turkey, with wisdom", he said.
President Donald Trump said Saturday he would speak to the crown prince "very soon" as he works to determine what, if any, consequences the US ally will face for the killing of a dissident journalist.
The source said dressing Madani up as Khashoggi and claiming he left the building was a plan hatched before Khashoggi's death, and shows that his killing was premeditated. "We are not going to throw our hands in the air and terminate..."
Saudi Arabia said on Saturday that Khashoggi was involved in "a physical confrontation, which resulted in his death".
During a joint interview with Britain and France, Mrs Merkel said that she condemned the killing of Mr Khashoggi "in the strongest terms".
"That is unacceptable in any government", al-Jubeir said on Sunday. "The assassination team then killed Khashoggi after the conversation ended".
In a speech on Sunday, Turkish President Tayyip Erdogan appeared to suggest he was getting ready to release some information about the Turkish investigation, and would do so at his weekly speech on Tuesday to members of his ruling AK Party. "All of this needs to be explained in all its details", President Erdogan said on Sunday.
The same man was seen in Khashoggi's clothing, according to the Turkish case, at the city's world-famous Blue Mosque just hours after the journalist was last seen alive entering the consulate on October 2.
That yet again adds to the pressure Saudi Arabia faces over the slaying of the Washington Post columnist.
"The Saudi account has been met with widespread global skepticism and allegations of a cover-up".
There has been speculation Khashoggi was murdered because of his open criticism of the Crown Prince but Saudi authorities insist the royal played no part in his death. "It's the only thing the Saudis will listen to", said Paul.
The Saudis' greatest concern is the United States, a crucial military ally against archrival Iran and a key source of the kind of foreign investment they will need to reform the economy.
"Khashoggi's clothes were probably still warm when Madani put them on", the senior Turkish official told CNN.
The Gulf kingdom admitted on Friday that the dissident journalist had died at its Istanbul consulate but claimed that he was killed in a brawl.
Speaking late Saturday Trump said he needs to learn more about the killing and will be working with Congress on the USA response.
Saudi Arabia is also Germany's second-largest weapons customer.
Khashoggi went missing on October 2 when he entered the consulate in Istanbul. "This is not an explanation; it is a cover-up", Mr. Ryan said. "So we have to use oil reserves", he said. We are determined to find out all the facts. "And I think we're inching our way there".