WASHINGTON — Hundreds of US public officials, police officers and soldiers are or have been involved with the far-right Oath Keepers militia, according to a report from an anti-extremism organization.

The Anti-Defamation League's Center on Extremism compared the names from a leak of Oath Keepers membership rolls with public records and social media.

Some alleged members have denied any affiliation with the group. Oath Keepers are accused of playing a key role in last year's Capitol riots.

The report raises fresh concerns about the presence of extremist ideology in law enforcement and the military.

"The Oath Keepers are a virulently anti-government, violent extremist group," Anti-Defamation League (ADL) chief executive Jonathan Greenblatt said in a statement on Wednesday.

Last year, a whistleblower group called Distributed Denial of Secrets published more than 38,000 names on the Oath Keepers' membership list — although experts estimate that the group's current active membership is much lower.

Analysis of the leaked data by the Anti-Defamation League (ADL) identified 81 people across the country who currently hold public office, or are running in November's midterm elections.

Researchers also found that nearly 400 current law enforcement officers and more than 1,000 former officers are connected to the group, along with more than 100 currently serving military personnel.

In its report released Wednesday, the ADL included a caveat that some in the database "may have initially joined because they were sold a watered-down version of the group, and some may have disavowed the group since signing up".

"That said, the range of individuals represented in the Oath Keepers leak shows the extent to which this extremist ideology has gained acceptance," the researchers wrote.

Several of the people on the ADL list have said they are not current members of the Oath Keepers or were never involved in the group.

Shawn Mobley, the sheriff of Otero County in Colorado, told the Associated Press that he had distanced himself from the group years ago.

"Their views are far too extreme for me," Mobley told the news agency.

Others in the report however have more definitive ties to the group, such as Wendy Rogers, a state senator from Arizona who has publicly declared her membership.

Rogers, who has repeated false claims that Donald Trump won the 2020 presidential election, is running for re-election in November.

The Oath Keepers were founded in 2009 by Stewart Rhodes, a former US Army paratrooper and Yale Law School graduate.

The pro-gun group was named after the oath of service that police, military and other officials take when joining.

Those taking the military oath, for instance, pledge to "support and defend the Constitution of the United States against all enemies, foreign and domestic".

Over the past decade, members have shown up at a number of protests and armed standoffs across the country.

More than a dozen members of the group were charged earlier this year in connection with the Jan. 6, 2021, storming of the US Capitol by supporters of former President Donald Trump.

A former Oath Keepers spokesman told a congressional committee investigating the Capitol attack that the group has come to embrace white nationalists and other "straight-up racists".

"I think we've gotten exceedingly lucky that more bloodshed did not happen because the potential has been there from the start," Jason Van Tatenhove said in July testimony before the committee.

Rhodes and four other Oath Keepers will go on trial later this month on charges of seditious conspiracy, a US Civil War-era charge that carries up to 20 years in prison. — BBC