RIYADH • Allegations that Saudi agents flew to Turkey and murdered one of the kingdom's leading critics would have sent shock waves through bilateral relations at any point.
But with the two countries already on opposite sides of some of the Middle East's defining rifts, the accusations - voiced in off-record briefings by Turkish officials and vehemently denied by Saudi rulers - are potentially even more explosive.
Each chilling leak about the possible fate of journalist Jamal Khashoggi, and the resultant international condemnation, makes a behind-the-scenes compromise that much harder.
Mr Khashoggi, who has been living in self-imposed exile for the past year, vanished on Oct 2 after he entered the Saudi consulate in Istanbul to obtain a document.
The Washington Post, citing unnamed US officials, reported on Wednesday that Saudi Crown Prince Mohammed bin Salman had ordered the abduction of Mr Khashoggi in order to get him back to the kingdom. The Saudi government has said it had nothing to do with his disappearance.
United States President Donald Trump said yesterday that the US authorities are "getting closer" to finding out what happened to the journalist, an issue that threatens to damage ties between the kingdom and Washington.
"We will probably know in the very short future. We have some incredible people and some incredible talent working on it. We don't like it. I don't like it. No good," Mr Trump said during an interview with a Fox News programme.
LOOKING FOR ANSWERS
We're being very tough. And we have investigators over there and we're working with Turkey, and frankly we're working with Saudi Arabia. We want to find out what happened... We're looking at it very, very seriously... I don't like it. No good.
U.S. PRESIDENT TRUMP, in an interview yesterday with Fox News' Fox & Friends programme.
DOUBTING SAUDI EXPLANATIONS
Is it possible there were no camera systems in a consulate, in an embassy? Is it possible that there was no Saudi camera system where this incident took place?... They (Saudi Arabia) have the most cutting-edge systems.
TURKISH PRESIDENT RECEP TAYYIP ERDOGAN, to Turkish reporters.
Turkish President Recep Tayyip Erdogan yesterday challenged Saudi Arabia to provide CCTV images to back up its version that Mr Khashoggi had left the consulate safely, indicating he did not find the current Saudi explanations sufficient.
"Is it possible there were no camera systems in a consulate, in an embassy? Is it possible that there was no Saudi camera system where this incident took place?" Mr Erdogan told Turkish reporters in comments published in newspapers.
The consulate said CCTV cameras were not working that day and dismissed the murder claims as "baseless".
Mr Erdogan said he cannot remain silent over Mr Khashoggi's fate, adding to growing differences between Turkey and Saudi Arabia.
Those disagreements run deep and extend far: from Turkey's support for a leading Islamist group that Saudi Arabia has designated as terrorists, to relations with Shi'ite power Iran and the Saudi-led boycott of Qatar.
Saudi Arabia and three allies broke ties with Qatar in June last year after accusing the gas-rich nation of financing terrorism and intervening in the affairs of other Arab states, accusations it denies.
Turkey responded to Saudi demands that it withdraw Turkish forces from Qatar by instead building up its military presence there. It also sent food, milk and other goods to help Qatar through the boycott.
The defiance angered Prince Mohammed, who labelled Turkey part of a "triangle of evil", lumping it together with Shi'ite power Iran and Islamic extremist groups.
In religion, Mr Erdogan has pushed back against Saudi Arabia's efforts to rebrand the form of Islam practised in the kingdom.
After Prince Mohammed said that Saudi Arabia was returning to a moderate version of the faith, Mr Erdogan shot back. During a speech in Ankara, he said Islam "cannot be either 'moderate' or 'not moderate'. It can only be one thing".
Mr Erdogan criticised the crown prince, saying "perhaps the person voicing this concept thinks it belongs to him. No, it does not belong to you".
Saudi Arabia and its closest Gulf allies have been enthusiastic backers of Mr Trump's offensive to isolate and weaken Iran, their chief regional foe.
That included waging war on Yemen's Houthi rebels, who the Saudis say are backed by Iran, in a military intervention that has deepened one of the world's worst humanitarian catastrophes.
Prince Mohammed warned in a March interview with the Wall Street Journal that war with Iran is likely in the next 10 to 15 years if pressure is not put on its ruling clerics.
In another interview with The Atlantic, the prince said that Iran's Supreme Leader Ayatollah Ali Khamenei was worse than Hitler, accusing him of trying to "conquer the world".
In contrast, Turkey has maintained trade ties with Iran and increasingly cooperated with Teheran in the war in Syria as its own security interests drifted away from those of traditional allies, including the US.
BLOOMBERG, REUTERS, AGENCE FRANCE-PRESSE