While Saudi Arabia's description of what happened to the elder Khashoggi has shifted several times, Turkish officials have said he was strangled shortly after he entered the Istanbul consulate and his body was dismembered.
"Without due orders and permissions, 15 people can not come from Saudi Arabia to kill their own citizen", Mr. Cavusoglu said.
According to Sabah newspaper, an 11-person Saudi team arrived in Istanbul on October 11, including chemist Abdulaziz Aljanobi and toxicology expert Khaled Yahya Al Zahrani.
Saudi Arabia acknowledged last month that Turkish evidence indicates that the Khashoggi's killing at the consulate was premeditated, shifting its explanation in an apparent effort to ease worldwide outrage over the death.
On Sunday, a report by a Turkish pro-government newspaper said Khashoggi's body was dismembered and put into five suitcases.
Geneva - Saudi Arabia told the United Nations on Monday it would prosecute those responsible for the killing of journalist Jamal Khashoggi at its Istanbul consulate, as Western states pressed it for a credible investigation.
Son - whose company has heavily invested in real estate companies like WeWork, Katerra and Lemonade -condemned the attack, but said his company has a "responsibility" to continue to invest the Saudis' funds.
Turkish President, Tayyip Erdogan, had repeatedly demanded for more information from Saudi Arabia.
India vs West Indies, 1st T20I
Rohit Sharma who has done exceptionally well with the bat and captainship will lead the young Indian side. The home team has won only two of eight T20 games, losing five; one match ended in a "no result".
"The question now is who gave the orders".
Jamal Khashoggi disappeared after entering the Saudi consulate in Istanbul on October 2.
It was not clear if the effective chief executive of the country, Crown Prince Mohammed bin Salman, would accompany his father.
Salah and Abdullah Khashoggi, who described their father as "courageous, generous and very fearless", said they have suffered weeks of agony and uncertainty following his disappearance and death.
At the end of January the Saudi prosecutor general's office said more than $100bn (£77bn) had been recovered following financial settlements with those being held. "It's easier to stick a label on him", Abdullah said in response to these claims.
"A thorough, conclusive and transparent investigation carried out in accordance with due process with results made public is essential", he said.
"I talked about that with the Saudi authorities and I just hope that it happens soon", he said.