HOUSTON (Texas: Special counsel John Durham concluded that the FBI should never have launched a full investigation into former US President Donald Trump's campaign and its alleged ties to Russia during the 2016 presidential election, according to a report compiled over a three-year period which was released Monday.

"We conclude that the (Justice) Department and FBI failed to uphold their important mission of strict fidelity to the law in connection with certain events and activities described in this report," Durham wrote.

Durham, a Trump-administration appointee, said the FBI used "raw, unanalysed, and uncorroborated intelligence" to launch the "Crossfire Hurricane" investigation into Trump and Russia. In contrast, he said the agency used a different standard when weighing concerns about alleged election interference regarding Democratic opponent Hillary Clinton's campaign.

"Neither US law enforcement nor the intelligence community appears to have possessed any actual evidence of collusion in their holdings at the commencement of the Crossfire Hurricane investigation," Durham continued.

Despite his findings of the FBI's wrongdoing, the special counsel did not recommend any new charges against individuals or "wholesale changes" regarding how the FBI handles politically charged investigations.

Durham did, however, strongly criticise the agency's behavior, saying that senior FBI personnel "displayed a serious lack of analytical rigor toward the information they received, especially information received from politically affiliated persons and entities."

"It is the Office's assessment that the FBI discounted or willfully ignored material information that did not support the narrative of a collusive relationship between Trump and Russia," the report continued. "An objective and honest assessment of these strands of information should have caused the FBI to question not only the predication for Crossfire Hurricane, but also to reflect on whether the FBI was being manipulated for political or other purposes. Unfortunately, it did not."

In the wake of the report, the FBI released a statement Monday saying it had taken steps to correct the agency's mistakes during the Trump-Russia probe.

"The conduct in 2016 and 2017 that Special Counsel Durham examined was the reason that current FBI leadership already implemented dozens of corrective actions, which have now been in place for some time. Had those reforms been in place in 2016, the missteps identified in the report could have been prevented," the statement said.

"This report reinforces the importance of ensuring the FBI continues to do its work with the rigor, objectivity, and professionalism the American people deserve and rightly expect."

Trump hailed the report's findings in a post on his Truth Social platform.

"WOW! After extensive research, Special Counsel John Durham concludes the FBI never should have launched the Trump-Russia Probe! In other words, the American Public was scammed, just as it is being scammed right now by those who don't want to see GREATNESS for AMERICA!" he said.

-- BERNAMA