The killing of journalist Jamal Khashoggi was planned days in advance, Turkish President Recep Tayyip Erdogan has told MPs from his ruling party.
He said Turkey had strong evidence Khashoggi was killed in a premeditated and “savage” murder at the Saudi consulate in Istanbul on 2 October.
He also called for the suspects to be tried in Istanbul.
He demanded Saudi Arabia provide answers about where Khashoggi’s body was, and who ordered the operation.
The Saudi kingdom has provided conflicting accounts of what happened to the Washington Post contributor. After weeks of maintaining he was still alive, the authorities now say the 59-year-old was killed in a rogue operation.
Tuesday’s address by President Erdogan coincided with the start of an investment conference in Saudi Arabia that has been overshadowed by the Khashoggi case, with dozens of government and business leaders pulling out.
Many world leaders have condemned the murder of the prominent Saudi critic and demanded a full investigation.
US President Donald Trump says he is not satisfied with the Saudi explanation but he has also highlighted the kingdom’s importance as a US ally.
President Erdogan said three teams of 15 Saudi nationals had arrived in Istanbul on separate flights in the days and hours leading up to the murder.
A day before the killing, he said, some members from the group travelled to Belgrad forest, near the consulate – an area searched last week by Turkish police looking for the body.
He also described how the team had removed the hard drives from the consulate’s surveillance camera system prior to the arrival of Khashoggi, who was visiting to obtain documents for his forthcoming marriage.
A man who looked like Khashoggi, wearing his outfit, glasses and a fake beard, was among a group who left the consulate the same day as the killing, the president added.
On Monday, CNN broadcast images appearing to show that Saudi operative leaving the consulate.
President Erdogan confirmed that 18 people had been arrested in Saudi Arabia over the case. However, he has not released any details of the evidence gathered.
He made no mention of any audio or video recordings reported by Turkish media in the days following the journalist’s disappearance.
“My demand is that 18 people be tried in Istanbul,” he told MPs from his ruling AK party, adding that “all those who played a role in the murder” would be punished.
He said the suspects included the 15 Saudi officials identified flying to Istanbul ahead of the killing, as well as three consular officials.
Mr Erdogan called for an independent commission to be set up to look into the case, but said he was confident of King Salman’s full co-operation.
He did not mention Crown Prince Mohammed bin Salman, widely seen as the most powerful figure in the kingdom and who many believe ordered the killing.
For a president not shy of confrontation, this could be another attempt to preserve the diplomatic relationship with Saudi Arabia, or was the result of pressure from Riyadh or Washington to hold back, says the BBC’s Mark Lowen in Istanbul.
The Turkish president had promised to reveal the “naked truth” about the killing, but his speech gave barely more detail than we knew, our correspondent says.
King Salman chaired a cabinet meeting on Tuesday, after which a statement said that Saudi Arabia would hold to account those responsible for the killing, whoever they may be,
State media also said the king and the crown prince had held a meeting with members of the Khashoggi family in Riyadh.
Saudi Arabia has given conflicting accounts up to now, initially saying Khashoggi had left the building alive, then later saying that he had been killed in a “fist-fight” inside the consulate.
On Sunday, Saudi Arabia’s foreign minister acknowledged Khashoggi had been murdered, but said the Saudi leadership had not been aware of the “rogue operation”. (Excerpts from BBC)