Investigators have found evidence to indicate that Saudi writerJamal Khashoggi was killed inside the Saudi consulate in Istanbul, a Turkish source told AP.
Euronews has not independently confirmed the report.
Khashoggi disappeared at the beginning of the month, having left his fiancée outside the building as he went to pick up a document.
The Saudi authorities have denied involvement and allowed Turkish authorities to search the consulate for nine hours on Monday.
Turkey's president Recep Tayyip Erdogan said some surfaces marked by "toxic materials" that had recently been painted over had been one area of interest.
Khashoggi was a prominent critic of Riyadh who left the country last year for the US where he wrote for the Washington Post.