A Texas-based street pastor is planning to sue the Fort Worth Police Department after his attorney said officers threatened him with arrest while he was evangelising at a Pride event in June.

According to the Christian Post, David Grisham, a longtime evangelist, was cited by Fort Worth police during the Trinity Pride Fest on June 27. In the now-viral video, an unidentified female police officer is seen warning him and another member of the street preaching team that they could be arrested.

The group continued questioning officers after being moved outside police barricades. The unidentified officer can be heard telling them: “If someone is offended by your talking, then we have a problem […] If they are offended by your speech, okay, I will write a ticket, and we’ll go from there.”

Police issued Grisham a citation for “unreasonable noise".

In a statement, his attorney, CJ Grisham, said the citation was indefensible because the city's noise ordinance requires officers to measure sound levels using a decibel meter before issuing a citation.

“This ordinance was not followed because no officer performed a decibel check,” said Grisham.

Fort Worth police disputed that account. A spokesperson for the department said that after officials “carefully reviewed the incident,” the issue arose when the group used “a bullhorn to amplify their voice.”

Attorney CJ Grisham rejected that explanation in a Facebook post.

“Fort Worth police is lying to the media and the public about why David H. Grisham was cited,” he wrote. “We have the full video. They used the bullhorn as the excuse, but the elements were not there even for that. They threatened to arrest him LONG before they even used a bullhorn.”

The police department also said it plans to provide “refresher training” to officers and new recruits on “First Amendment protections".