Qatar knew of an Iranian plan to attack four ships off the UAE coast in May but failed to warn its US, French and British allies, according to a western intelligence report.

Two Saudi tankers, a Norwegian tanker and a UAE vessel were targeted by explosions near the port of Fujairah on May 12 amid rising tension between the United States and Iran over US sanctions seeking to block all Iranian oil exports.

“Credible intelligence reports indicate that the IRGC-Quds Forces Naval unit is responsible for the Fujairah Port attacks, and the elements of civilian government of Iran, as well as the State of Qatar, were aware of the IRGC’s activities,” according to the report, which was obtained by Fox News.

Iran’s Islamic Revolutionary Guard Corps has been designated as a foreign terrorist organisation by the US, which accused Iran of being behind the attacks. A preliminary report from a joint investigation led by the UAE, Saudi Arabia and Norway said a "state actor" was most likely behind the attacks.

The US State Department declined to comment but a British MP who received the report described it as “very alarming”. French senator Nathalie Goulet, a major figure in European counterterrorism efforts, told Fox News she was “very concerned” after seeing the report.

The UAE, Saudi Arabia, Bahrain and Egypt cut off ties with Qatar in June 2017 over its support for extremist groups and close relations with Iran, seen as a destabilising force in the region.

British MP Ian Paisley Jr told Fox News the intelligence report “requires serious and immediate investigation by my own government”.

“If proven correct, this poses serious questions for our alliances in this region,” he said.

Ms Goulet said she would “raise questions with colleagues in other countries with strong connections in the Middle East such as Britain and with our government,” she said. “I will send the report to the head of the security department and also the minister of defence.”

Fox News said Qatar, which hosts the largest US military base in the region, did not respond to requests for comment on the report.

Ms Goulet, who has authored a report for Nato on terror finance, questioned Qatar earlier this year over allowing the Al Qaeda financier Khalifa Al Subaiy access to his bank account despite an asset freeze.