U.S. investigators are in Qatar to help probe the alleged hacking of the Gulf state's news agency website, Arab and U.S. law enforcement officials said.
Qatar said last week that hackers had posted fake remarks by the emir, Sheikh Tamim bin Hamad al-Thani, that purportedly had him criticizing some leaders of fellow Gulf Arab states and calling for an easing of tensions with regional foe Iran.
Gulf states have rejected Qatar's explanation, leaving local media to unleash a barrage of attacks on the emir, accusing him of cosying up to Iran.
The row erupted days after the first visit by U.S. President Donald Trump to Saudi Arabia, in which he sought to galvanize the fight against Islamist militancy and Iran, which Washington sees as a threat to regional stability.
An Arab official, who asked not to be identified, said that experts from the Federal Bureau of Investigation (FBI) had been helping with the probe since last week.
"The results of the investigation will be made public this week," the official told Reuters, adding that two countries were also assisting with the probe, but declining to give further details.
In Washington, a U.S. law enforcement official confirmed that an FBI team was in Doha "working with Qatari authorities to investigate the alleged hacking incident into its state news agency".
The officials gave no details of the number of people on the U.S. team or progress in the investigation.
The rift has revived a 2014 row that erupted over alleged Qatari support for the Muslim Brotherhood and meddling in the affairs of other members of the Gulf Cooperation Council (GCC).
Saudi Arabia and the United Arab Emirates, both members of the GCC, have labeled the Brotherhood a terrorist organization.
Qatar's emir has visited Kuwait in what appeared to be an attempt by the Kuwaitis to mediate between Doha on one side and Abu Dhabi and Riyadh on the other.
There was no immediate sign of a breakthrough.
Saudi and UAE media on Saturday continued their criticism of Qatar.
One newspaper posted a story citing what it said were Qatari ties with Israel, using an old picture of the then Qatari emir Sheikh Hamad bin Khalifa al-Thani shaking hands with the late Israeli President Shimon Peres.
Most Gulf Arab states have no official ties with Israel. Qatar briefly hosted an Israeli trade office but it was shut several years ago.