President Tayyip Erdogan, who has demanded more information from Saudi Arabia, said on Tuesday Istanbul's chief prosecutor had asked Mojeb to disclose who sent the team from Riyadh which is suspected of involvement in the killing.
Hatice Cengiz, the fiancée of slain Saudi journalist Jamal Khashoggi.
Often on the receiving end of Khashoggi's criticisms, Saudi Crown Prince Mohammed bin Salman had earlier lauded the "unique" cooperation between Saudi and Turkey.
Turkey alleges a Saudi hit squad from Saudi Arabia traveled to Istanbul to kill the journalist and then tried to cover it up.
Turkey says that despite all well-intended efforts, authorities have unable to reach "concrete results" in the investigation of Khashoggi's killing.
Saudi officials at first insisted that Khashoggi left the compound on October 2 after completing his paperwork. Khashoggi was murdered by Saudi officials, who claim the writer died as a result of an "altercation".
Saudi Arabia's top prosecutor Saud al-Mojeb walks to board a plane to leave Turkey, in Istanbul, Wednesday.
He has met with Istanbul's chief prosecutor Irfan Fidan twice, and inspected the Saudi consulate.
But President Donald Trump has ruled out major actions such as ending arms sales to the kingdom, the largest foreign buyer of US weapons.
Saudi Arabia has detained 18 people and dismissed five senior government officials as part of the investigation into Khashoggi's murder.
Mojeb left Turkey on Wednesday evening after a three-day visit during which he also held talks at the offices of Turkey's National Intelligence Agency (MIT).
Al-Mojeb also visited the Saudi consulate where Khashoggi went missing, Al Jazeera reported.
Khashoggi's death has brought near unprecedented global scrutiny on Saudi Arabia and its powerful crown prince.
Under mounting global pressure, Saudi Arabia has changed its narrative about Khashoggi's killing several times, and has recently acknowledging that Turkish evidence shows it was premeditated.
"No need to prevaricate", Erdogan told reporters in Ankara.