A central California police officer is under investigation after images surfaced online purportedly showing him participating in a counterprotest alongside Proud Boys members over the weekend.

The Fresno Police Department said Sunday it launched an internal affairs investigation after it first became aware of the photos and images depicting the officer purportedly marching with members of the Western chauvinist group outside the Tower Theatre.

Activists have been demonstrating at the theatre to protest its sale to a church viewed by some as anti-LGBTQ, and counterprotesters led by the Proud Boys have often shown up, the Fresno Bee reported.

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"Although at this point these are merely allegations, and the matter will be fully investigated, it is important to maintain the integrity and legitimacy of our police department," Fresno Chief of Police Paco Balderrama said in a statement. "Any allegations of actions unbecoming of a police officer or the affiliation with any alleged criminal or hate group will always be investigated and addressed. Fair and impartial policing are extremely important in our society. There is no place in our police ranks for any biased, racist or anti-Semitic views."

Balderrama did not name the officer, but the Fresno Bee identified him as Rick Fitzgerald.

Fitzgerald was spotted on a YouTube video posted by former Proud Boys member Eddie Block, whose home was raided by the FBI in January following the Jan. 6 U.S. Capitol riot, the newspaper reported.

The livestream captured Fitzgerald outside the Tower Theatre wearing clothing identifying himself as "Sheepdog" with a group called "Sons of ‘76." Social media users said that same man was seen in photos from a Sacramento demonstration in November 2020 wearing the signature black top and yellow kilt worn by Proud Boys members, and a vest labeled "Sheepdog" and a "thin blue line" American flag.

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"These images are extremely disturbing and are being taken very seriously," Fresno Mayor Jerry Dyer, who previously served as the city’s police chief for 18 years, said in a statement on Twitter. "As the mayor of this city, I will not tolerate any city of Fresno employee belonging to organizations that promote views of supremacy, racism or criminal conduct. This matter is under investigation and appropriate action will be taken to address any misconduct."

The officer was placed on administrative leave and stripped of his police powers pending the results of the internal investigation. 

Fresno Police Officers Association, the union representing rank-and-file officers, said it fully supports Balderrama in his decision to initiate a "thorough and objective" investigation into the matter.

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"The investigation should be based on facts and evidence, free of political influences, purposed for discovering the validity of the allegations at hand," the union said in a statement. It also echoes the sentiments of Dyer, "recognizing that racism, discrimination and criminal conduct among our ranks is absolutely intolerable," and the union "respects the constitutional rights of all persons and opposes any group or individual that would use violence or other illegal means to suppress the rights of others."