A man from Portland, Oregon says he was attacked by a member of the far-right Proud Boys group who has links to a Republican Senate candidate in Washington state.

Tim Ledwith, 34, said he was punched by Tusitala “Tiny” Toese, 22, who is aligned with the Proud Boys, a “western chauvinist” group founded by Gavin McInnes, a co-founder of the Vice Media empire.

Toese is also a prominent member of Vancouver, Washington-based Patriot Prayer, a group that has staged rallies that have often turned violent in the Pacific north-west over the past year. Patriot Prayer is led by Joey Gibson, a Republican candidate in the US Senate primary in Washington.

Tim Ledwith’s injuries following the alleged attack by Tsuitala ‘Tiny’ Toese. Photograph: Handout

Ledwith said the attack happened in a busy shopping area in Portland at around 2.30pm on Friday 8 June. Toese and two other men had been yelling at strangers from a truck, he said.

“They were yelling: ‘Support Trump, build the wall,’” Ledwith said.

Ledwith responded with a profanity, he said, and the men stopped their vehicle. Ledwith said Toese and another man, Proud Boys and Patriot Prayer supporter Donovan Flippo, got out.

“They were calling me a faggot and slinging epithets at me,” Ledwith said. “Tiny walked over calmly and … punched me in the face. I’m like, half his size. I was not a threat to them. I’m 34 years old, not 17. This is not a thing that happens to me day-to-day.”

Ledwith said the punch knocked him to the ground and opened a gash in his lip. He was treated at hospital, he said, receiving several stitches.

A witness, who did not wish to be identified, told the Guardian she saw the attack from a block away. Toese, she said, punched Ledwith. Flippo, she said, stood beside Toese but was not physically involved. Ledwith offered no physical provocation, the witness said, and did not respond violently.

Photos showed Ledwith’s injuries and Flippo walking towards the pickup truck, wearing a T-shirt marked “Antifa Removal Service”. The pickup, which carries Washington plates, is registered to Russell Schultz of Vancouver, Washington, a known attendee at Patriot Prayer rallies.

On 4 June 2017, a Patriot Prayer rally was held in Portland after a double murder on a commuter train allegedly carried out by a man who attended a Patriot Prayer event. The event featured a speech by the chair of the local Republican party and demonstrations by thousands of counter-protesters. Subsequent marches have degenerated into open brawls.

The Facebook pages of Toese, Flippo and Schultz feature videos, memes and photography of violence, often carried out by Proud Boy members, at Patriot Prayer events. All three have posted video of a violent rally in Portland on 3 June this year.

Toese was arrested at Patriot Prayer events in Portland last August for disorderly conduct, and again in December for disorderly conduct, harassment, assault, and an outstanding warrant.

The publication Willamette Week reported violence from Toese in Portland as far back as May 2017. Video from the 3 June rally shows him once again brawling with counter-protesters.

Ledwith said he had participated in two counter-protests at Patriot Prayer rallies. At the 4 June 2017 rally, he received a citation for disorderly behavior and was released by National Park Service officers. He thought the men who allegedly attacked him did not recognize him.

Toese, Flippo and Schultz did not respond to requests for comment.

The Patriot Prayer leader Joey Gibson speaks during a rally in Berkeley, California. Photograph: Marcio Jose Sanchez/AP

Gibson announced his Senate candidacy in February. He is seeking to progress from a crowded primary to challenge the Democratic incumbent, Maria Cantwell, in November.

Asked about the alleged attack, Gibson responded in a text message that he had only heard rumors about the attack on social media, but “I didn’t pay attention because I hear stuff like that all the time”. He said he would “ask around” about the incident.

A Portland Police Bureau (PPB) spokesman confirmed that Ledwith reported an assault on Tuesday, and that it had been referred to the detective division. The investigation was ongoing.

Earlier, the PPB confirmed that officers were called to the scene on Friday by two people. One call came from an employee of a local business, police said, and one from someone who “appeared to know the person that was reportedly injured”.

The Southern Poverty Law Center lists the Proud Boys as a hate group. Earlier this month, speaking to the Guardian in New York, McInnes praised Patriot Prayer. In the interview, he compared Gibson to an imprisoned British anti-Islamic activist, Stephen Yaxley-Lennon, known as Tommy Robinson.

Both men, he said, “have an electricity that is almost divinity”.