SPOKANE, Wash. — A Washington state lawmaker took part in “domestic terrorism” against the United States during a 2016 standoff at a wildlife refuge in Oregon and traveled throughout the West meeting with far-right extremist groups, according to an investigative report released Thursday.

The report prepared for the state Legislature said Rep. Matt Shea, a Republican from Spokane Valley in eastern Washington, also found that he trained young people to fight a “holy war," condoned intimidating opponents and promoted militia training by the Patriot Movement for possible armed conflict with law enforcement.

Shea was suspended from the state House Republican Caucus Thursday evening and advised to resign, House Minority Leader J.T. Wilcox tweeted. “He cannot use House Republican staff, he cannot meet with the caucus, his office will be moved,” Wilcox said. Shea will also be removed from his House committee assignments.

The incoming House Speaker, Democratic Rep. Laurie Jinkins, said the report had been forwarded to federal prosecutors and the FBI. She said her caucus would continue to work with Republicans to explore options based on the report's findings.

Both Democratic and Republican politicians had earlier demanded Shea's resignation.

In a statement posted to Facebook on Thursday night, Shea called the investigation "a sham" and compared it to the impeachment inquiry against President Donald Trump that resulted in Trump's impeachment this week.

"Like we are seeing with our President, this is a sham investigation meant to silence those of us who stand up against attempts to disarm and destroy our great country," he wrote, in part. "I will not back down, I will not given in, I will not resign. Stand strong fellow Patriots."

Prior to the release of the report, prepared by an outside investigator, Shea said he has been denied any opportunity to review and respond to it. The report noted Shea declined to be interviewed as part of the probe.

“Due process is the right of every citizen, and should be afforded to all members of the House regardless of their views or party affiliation,” Shea said.

The investigative team, headed by a former FBI agent and a former law enforcement officer, was hired in July.

The team's findings, first reported by the news website Crosscut, said: “Investigators obtained evidence that Representative Shea planned, engaged in, and promoted a total of three armed conflicts of political violence against the United States ... in three states outside the State of Washington over a three-year period to include 2014, 2015 and 2016."

One of the findings of the report was that Shea “participated in an act of domestic terrorism” when in 2016 he visited the Malheur National Wildlife Refuge in Oregon in support of its armed occupation by two sons of rancher Cliven Bundy.

Shea "engaged in conversations with Ammon Bundy and other militia members in the planning and preparation of the armed takeover of the Malheur National Wildlife Refuge in Burns, Oregon,'' the report said.

Shea issued a press release on Dec. 11, 2015, asking for patriot and militia groups to rally in Harney County, Oregon, against the U.S. government, the report said.

After the occupation of the wildlife refuge ended, Shea posted on his Facebook page: “After much prayer, I'm afraid violence might be necessary to take our country back," the report said

Shea also went to Cliven Bundy's Nevada ranch in 2014 during a standoff with FBI agents in a dispute over grazing rights. And in 2015, in Idaho, Shea resisted the planned removal of firearms from a military veteran who was not eligible to have them.

The report also said Shea in 2012 engaged in the intimidation of a political opponent when he posted a photo of himself on his Facebook page standing in front of the opponent's home, and refused to remove the photo despite requests from his opponent, said GOP officials and law enforcement.

Earlier this year, reports of a 2017 online chat that included Shea surfaced in the Guardian and later were expanded by The Spokesman-Review newspaper. That chat indicated the lawmaker joined a discussion in which others suggested violence against left-wing protesters.

Based on transcripts of the chat, there's no indication Shea advocated violence himself, although at one point he offered to do background checks on political opponents.

The texts came after Shea, a lawyer who was first elected in 2008, attracted international attention after a document he wrote laid out a ‘’biblical basis for war'' against gay marriage and abortion. He later said the document was taken out of context.

Shea has also pursued creation of a 51st state in eastern Washington that would be called Liberty and run on biblical principles.

The Army veteran hosts a weekly show on the American Christian Network and in 2017 complimented members of Team Rugged, a group that one member said provides special-forces-type gun training for young men so they can be effective in Christian warfare.

Shea last year lost a House leadership position after acknowledging he distributed the “biblical basis for war” document that also calls for killing non-Christian males who refuse to follow fundamentalist biblical law.

Shea is popular in his very conservative district and was re-elected in 2018 with 58% of the vote.