Turkish sources have said previously that authorities have an audio recording purportedly documenting the murder of the Saudi journalist.
The existence of such a recording has never been officially confirmed.
Speaking before his departure for France to attend commemorations to mark the 100th anniversary of the end of World War I, Erdogan said Saudi Arabiaknows Khashoggi's killer is among a group of 15 people who flew into Istanbul hours before the October 2 killing.
"We gave the tapes. We gave them to Saudi Arabia, to the United States, Germans, French and British, all of them. They have listened to all the conversations in them," Erdogan said.
Sources told Al Jazeera on Saturday that Turkish police ended the search for Khashoggi's body, but that the criminal investigation into the 59-year-old's murder would continue.
Al Jazeera learned on Friday that traces of acid were found at the Saudi consul general's residence in Istanbul, where the body was believed to be disposed of with the use of chemicals.
The residence is at walking distance from the Saudi consulate, where Khashoggi - a Washington Post columnist critical of the Saudi government and the all-powerful Crown Prince Mohammed bin Salman - was killed by a team of Saudi officers and officials.
Saudi Arabia has changed its narrative about the murder several times amid international outcry and intensifying scepticism over its account.
After insisting for more than two weeks that Khashoggi had left the consulate, it then admitted the journalist had died in a fistfight inside the building. Later, Riyadh conceded Khashoggi was killed in a premeditated murder, but that the murder was an unplanned "rogue operation".
However, Erdogan has accused the "highest levels" of the Saudi government of ordering the hit, while some officials have pointed the finger at the crown prince - a charge Riyadh denies.
Meeting with Trump
Speaking before his departure, Erdogan also said he might meet with US President Donald Trump in Paris during the commemorations.
"When we go to Paris, we will try to secure an opportunity and we will realise a bilateral meeting," Erdogan said.
"It happened as he was getting on the plane to go to Paris to meet with Trump. Erdogan is making it very clear that everyone knows what has happened, everyone who is a significant player in the region has the evidence."
Osman Sert, research director at Ankara Institute, said that Ankara will now attempt to "put pressure" on Washington, a major Saudi ally, but added that "there is a good atmosphere for the Turkish-American relations to go forward during this case".
"The public's priority should be to find out who committed this crime and who ordered this crime," he said.
"What should be done right now is Turkey shouldn't be left alone against the Saudis. The Europeans and Americans should stand with Turkey."
Elshayyal also said that Erdogan's remarks marked the first time Turkey's president "had spoken directly about those audio recordings", adding that the move raised doubts on claims that the taps might have obtained "in some kind of clandestine tapping by the Turkish authorities".
Turkish and Saudi officials have carried out joint inspections of the consulate and the consul-general's residence, but Erdogan said some Saudi officials were still trying to cover up the crime.
Elshayyal said that Saudi officials, despite officially claiming that they would cooperate with their Turkish counterparts, so far have not only refused to do that but possibly tried to tamper with the ongoing investigation.
"They namely did this by sending in chemical experts [in the consulate and consul-general's home] to destroy evidence," he said.
"They also denied Turkish requests to once again search the consul-general's home, after Turks found samples of chemicals in the garden of the residence."
Istanbul's chief prosecutor said on October 31 that Khashoggi was strangled as soon as he entered the consulate and that his body was dismembered, in the first official comments on the case.
Saudi Arabia has said it arrested 18 people and dismissed five senior government officials as part of an investigation into Khashoggi's killing
Ankara also seeks extradition of the suspects.