"It is obvious that 18 people are involved in this killing, both the Saudi foreign minister and other officials should reveal this local cooperator and the facts about these 18 people. Let us know whoever this person is and we will find them."
The Turkey president has been pushing the Saudi leadership for weeks to reveal circumstances behind the killing of Khashoggi who was murdered inside the Saudi consulate in Istanbul.
"Our prosecutor told the Saudi prosecutor that the prosecution could be carried out in Turkey since the location of the crime is Istanbul," he said, adding,"our prosecutor also asked some questions that I previously brought up. Firstly, who sent the group of 15 people here?"
Saudi prosecutor Saud Al Mojeb had held talks with Istanbul's prosecutor Irfan Fidan over two days on the death of Jamal Khashoggi as Turkey kept demanding answers from the Saudi officials.
"We cannot leave this issue unsolved, we need to solve it now. There is no point in procrastinating or trying to save some people from under this," Erdogan declared.
On Monday, Turkish foreign minister Mevlut Cavusoglu had asked Saudi Arabia to conclude the investigation as soon as possible.
"The whole truth must be revealed," he said. "We believe (Mujeb's) visit is important for these truths to come out."
Saudi Arabia had earlier denied Khashoggi was murdered but later made a U-turn to declare that he was killed inside the consulate. Crown Prince Salman called the killing "repulsive" and promised to bring the killers to justice while denying personal involvement in the murder. The Saudi leadership blamed the killing on a "rogue operation".
Saudi Arabia has sacked five intelligence chiefs, including two who were part of Prince Mohammed's inner circle.