(Adds details throughout, context, Nunes reaction)
By Patricia Zengerle
WASHINGTON, Dec 7 (Reuters) - The U.S. House of Representatives Ethics Committee on Thursday cleared the chairman of the House Intelligence Committee of charges that he had disclosed classified information, potentially clearing the way for him to resume leadership of the panel's Russia investigation.
Republican Representative Devin Nunes, who had consistently denied wrongdoing, thanked the committee for its finding, but said the probe had taken too long and the accusations against him were politically motivated.
Nunes stepped aside from leading the intelligence committee's investigation of Russia and the 2016 U.S. presidential election in April as the Ethics panel said it was investigating allegations that he had disclosed classified information.
The accusations against Nunes arose after President Donald Trump tweeted in March, without giving evidence, that former President Barack Obama, a Democrat, had wiretapped him as he competed for the presidency.
Two and a half weeks later, Nunes, a Trump ally, told reporters that an unidentified source had shown him intelligence reports containing "unmasked" names of Trump associates swept up in foreign surveillance, prompting accusations that Nunes had disclosed classified information to provide cover to Trump.
Trump's fellow Republicans in Congress have frequently raised the "unmasking" issue during the investigation of allegations that Russia sought to influence the 2016 U.S. election to boost Trump's chances of defeating Democrat Hillary Clinton and whether Trump associates colluded with Russia.
Russia had denied the accusations, and Trump has dismissed any talk of collusion.
Some Republicans contend that the potential surveillance of Americans and release of their names, possibly for political purposes, should be addressed by investigators. Former Obama administration officials have denied such accusations and labeled the issue a distraction from serious investigations of U.S. election integrity.
Nunes criticized the ethics panel for taking "an unbelievable eight months" to dismiss the matter, and called on the panel to publicly release all transcripts related to his case.
Ethics committee staff could not immediately be reached for comment. In a statement, the panel said intelligence experts had concluded the information Nunes disclosed was not classified, so it would take no further action and the matter was closed.
It was not clear whether Nunes would formally resume leadership of the House Intelligence Committee's investigation. His spokesman did not immediately respond to a request for comment. Republican Representative Mike Conaway has been leading it since April.
Nunes has remained chairman of the intelligence panel. (Reporting by Patricia Zengerle; Editing by James Dalgleish)
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