The report said senior members of the Emirati government discussed the hacking plan a day before a story appeared on the official Qatar News Agency quoting Qatar's emir, Sheikh Tamim Bin Hamad Al Thani, allegedly praising Iran and saying Qatar has a good relationship with Israel.
The comments were then cited by Saudi Arabia, UAE, Bahrain and Egypt as the spark that reignited an even more serious diplomatic crisis than had previously occurred in 2014 over Doha's support for Islamist groups across the region, and allegations that it funds terrorist groups in Libya, Syria and elsewhere.
A CNN report titled, "US suspects Russian hackers planted fake news behind Qatar crisis", citing anonymous U.S. officials, claimed that intelligence gathered as part of an FBI investigation into the hack indicated that unnamed Russian hackers could be behind the intrusion.
'The UAE had no role whatsoever in the alleged hacking described in the article.
The officials said it was unclear if the UAE hacked the websites or paid for it to be carried out, the newspaper reported.
Yousef al-Otaiba, the UAE ambassador to Washington, told the Post: "What is true is Qatar's behaviour". Qatar has denied the accusations. "But we can not have a member who is undermining us and supporting extremism", he said.
Qatar has repeatedly charged that its sites were hacked, but it has not released the results of its investigation, the Post reported.More news: Magellan Midstream Partners LP
Al Jazeera's Heidi Zhou-Castro, reporting from Washington, DC, said this is new information and the US Department of State has yet to officially respond. "Inciting violence, encouraging radicalisation, and undermining the stability of its neighbours".
The UAE, however, has long-standing grievances with Qatar, as do the other three blockading states, as all object to Qatari media outlets' coverage offering more conflicting viewpoints than is common within the Middle East.
"You can not be both our friend and a friend of al-Qaeda", he said, repeating allegations - denied by Qatar - that the country funds extremists.
Throughout the crisis President Donald Trump and his White House have been at odds with the State Department led by Rex Tillerson who has emphasized the need for compromise and said the row could destabilize anti-Daesh efforts.
With US spy agencies now apparently briefing against them, Qatar's antagonists may conclude US sympathy for their position is rapidly dwindling.
Mr Gargash called for "a regional solution and global monitoring" to solve the Gulf crisis.
Arab states that have cut ties with Qatar vowed Wednesday to maintain their boycott of the emirate, criticising its "negative" response to their list of demands to end the diplomatic crisis.