The image shows the date and time (13:14) and bears a caption in Turkish with the journalist's name and that he was arriving at the consulate.
Turkish officials allege he was murdered inside the consulate.
The Turkish government is looking into Khashoggi's disappearance.
But as more than a week has passed since he was last seen, the possibility that he is alive has dwindled.
After several of his friends were arrested, his column was cancelled by the al-Hayat newspaper and he was allegedly warned to stop tweeting, Mr Khashoggi left Saudi Arabia for the USA, from where he wrote opinion pieces for the Washington Post and continued to appear on Arab and Western TV channels.
"If the assassination of Jamal Khashoggi is proved, I invite all walks of life in Saudi Arabia to cooperate in a legal measure and change the political system through civil disobedience", Farhan al-Saud wrote on his twitter page on Monday. One was an autopsy expert, presumably there to help dismember the body, the official said.
The Washington Post, for which the self-exiled Khashoggi wrote columns over the past year, pressed for release of evidence. Nor has the Turkish president disclosed specific evidence to back up that allegation. "It is (the duty) of the consulate officials", Erdogan said while visiting Hungary. Turkish officials have said they fear the columnist was killed there.
However, activists protesting outside the consulate said more needed to be done. That need for secrecy could also hamper any efforts to prosecute any Saudi agents involved.
"When this person enters, whose duty is it to prove that he left or not?" Erdogan has said he would await the results of an investigation. Marco Rubio, R-Fla., tweeted Sunday that if "deeply disturbing" reports of Khashoggi's murder were confirmed, "The United States and the civilized world must respond strongly, and I will review all options in Senate".
Saudi Arabia is a longtime ally of the United States, but on Monday senior US officials expressed alarm over Khashoggi's disappearance.
Turkish Foreign Ministry spokesman Hami Aksoy said earlier today that a "search will be conducted in the [consulate] building as part of the investigation".
President Donald Trump and European leaders all have called on Riyadh to explain what happened to the 59-year-old journalist who has criticized the Saudi government.
He noted 47 USA senators recently voted to ban arms sales to Saudi Arabia - four short of a majority.
He has been critical of some policies of the crown prince and Riyadh's intervention in the war in Yemen.
But with Khashoggi unseen for days, there were signs Tuesday that the pressure was increasing.
Meanwhile, the United Nations human rights office urged both countries to investigate the case. A Turkish official linked the call signals of the two twin-engine Gulfstream IV planes to those that investigators believe carried the 15 Saudis. He served as an adviser to senior Saudi officials.
The Foreign Office would face charges of hypocrisy if, after its outrage over the attempted assassination by Russian Federation of the former spy Sergei Skripal in Salisbury, it remained silent over an alleged murder by the Saudi government. Its passengers checked into two hotels near the consulate and booked rooms until October 5. It is unclear whether those on board traveled to either the consulate or the residence. Turkish employees of the residence had unexpectedly been told not to report for work that day, the newspaper said.
Khashoggi was one journalist who chose to "report the reality".