(CNN)A Republican state lawmaker in Washington is accused of participating "in an act of domestic terrorism against the United States," according to a new report released Thursday by the Washington State House Republicans on their website.

       According to the report, Rep. Matt Shea is the subject of an investigation that was commissioned by the Washington State House Representatives to find out whether he "engaged in, planned, or promoted political violence." Rampart Group LLC investigators say the investigation was sparked by "public allegations made against [Shea] in news media and online reporting," the report said.

       According to the report, "[i]nvestigators have obtained evidence that Representative Shea, as a leader of the Patriot Movement, planned, engaged in, and promoted a total of three armed conflicts of political violence against the United States Government in three states outside the State of Washington over a three-year period to include 2014, 2015 and 2016."

       Investigators say Shea declined their request for an interview. CNN has been unable to reach him for comment.

       Late Thursday, there was a Facebook post that appeared to be from Shea, saying in part, "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. I will not back down, I will not give in, I will not resign."

       Shea has been suspended from the caucus and will be removed from his committees, House Republican Leader J.T. Wilcox said in a statement.

       "Allegations this serious, many supported by his own communications and associates, justify this immediate action," Wilcox said.

       Shea remains in the Legislature as an elected member and previously has served as the House GOP caucus chair.

       Wilcox said the Washington State House of Representatives referred the full report to the U.S. Attorney's Office and FBI. It's not clear whether he is facing any charges.

       FBI Seattle's spokesman, Steve Bernd, told CNN the agency has received the report about Shea, but have no further information.

       CNN has also reached out to the U.S. Attorney's Office for comment.

       The Washington State Legislature is not currently in session. A member cannot be expelled unless the Legislature is in session and then it requires a 2/3 vote, according to Bernard Dean, Chief Clerk of the Washington House of Representatives.

       "A number of responses are possible, including expulsion or censure. Members will continue to discuss these and other options over the coming weeks," Dean said.

       Shea has been suspended from the caucus and will be removed from his committees, House Republican Leader J.T. Wilcox said in a statement.

       "Allegations this serious, many supported by his own communications and associates, justify this immediate action," Wilcox said.

       Shea remains in the Legislature as an elected member and previously has served as the House GOP caucus chair.

       Wilcox said the Washington State House of Representatives referred the full report to the U.S. Attorney's Office and FBI. It's not clear whether he is facing any charges.

       FBI Seattle's spokesman, Steve Bernd, told CNN the agency has received the report about Shea, but have no further information.

       CNN has also reached out to the U.S. Attorney's Office for comment.

       The Washington State Legislature is not currently in session. A member cannot be expelled unless the Legislature is in session and then it requires a 2/3 vote, according to Bernard Dean, Chief Clerk of the Washington House of Representatives.

       "A number of responses are possible, including expulsion or censure. Members will continue to discuss these and other options over the coming weeks," Dean said.