At a summit of the Group of 20 in Buenos Aires, the Turkish leader took a firm tone on Saudi Crown Prince Mohammad bin Salman (MBS).
Saudi Arabia has announced the detention of 18 nationals and vowed to probe the killing of Khashoggi, a royal confidant turned critic who was killed and dismembered when he visited the kingdom's Istanbul consulate on October 2, to handle paperwork for his planned wedding.
"It's essential that these people are tried in Turkey in order to eliminate any question marks that the international community may have," Erdogan told reporters, Al Jazeera reported.
"Whoever has ordered and implemented this violent crime should be found out at once. Unless the perpetrators are found out, the whole world and the Islamic community shall not be satisfied."
Erdogan said the Saudis have refused to help Turkish prosecutors who sought information including the whereabouts of Khashoggi's body and the identities of accomplices said to have supported the visiting Saudi hit squad.
The Turkish leader, who has been vying for influence in the region with Saudi Arabia, said he did "not wish to cause any damage" to the royal family.
But he criticized Prince Mohammad, saying that during the summit the 33-year-old heir apparent gave an "unbelievable explanation" on Khashoggi's killing that denied any Saudi official role.
Erdogan said that only one G20 leader - Canadian Prime Minister Justin Trudeau - raised the writer’s death in their group meeting.