"One probability is that they left the country three to four hours after committing the murder. They may have taken out Khashoggi's dismembered corpse inside luggage without facing problems due to their diplomatic immunity," said Akar, according to CNN Turk.
Turkey has said a 15-man team was involved in the killing.
Last week, a Saudi prosecutor said the body was dismembered, removed from the building and handed to an unidentified "local co-operator".
On Saturday, US news organisations reported that the CIA had concluded that responsibility stretched to the very top of the country's ruling family.
However, Trump, who is under pressure to distance the US from a close ally, has pushed back, saying the conclusion was "very premature".
"We'll be having a very full report over the next two days," Trump said yesterday.
His position was backed by the State Department, which issued a statement saying the US had not yet come to a final conclusion about who ordered the killing.