Newly released FBI records reveal that Richard Masato Aoki, widely revered as a radical hero in the San Francisco Bay Area in the 1960s, had a deep relationship with the FBI, informing on his fellow Asian activists and on Black Panther Party leaders Huey Newton and Bobby Seale.

Going beyond previously disclosed FBI records that outlined his role as an informant, the documents show that while acting as a militant leader, Aoki covertly filed more than 500 reports with the FBI between 1961 and 1971 on a wide range of activists and political groups in the Bay Area.

Aoki, who grew up in West Oakland, was a well-known figure in the Bay Area’s activist community and one of the earliest members of the Black Panthers who publicly acknowledged giving them some of their first guns. After he died in 2009 at age 70, he achieved new notoriety with the release of a feature documentary about him and a biography. Neither work mentioned his relationship with the FBI.

The records show that FBI agents considered Aoki a valuable informant with “top level” access to the Panthers. The bureau assigned him a “confidential source symbol number” to protect his identity — SF 2496-S — and took extra security measures. One document said disclosure that he was an informant could “have an adverse effect upon the national defense interests.”

Aoki had said publicly that he gave the Panthers some of their first guns, which Seale confirmed in his autobiography. The Panthers openly and legally carried guns obtained from various sources on their “community patrols” against police brutality.

Their use of weapons publicized their cause but also led to heightened law enforcement scrutiny and fatal shootouts with police.

However, the newly released records do not indicate whether the FBI was aware of Aoki’s role in arming the Panthers or whether the bureau was involved in it. If the FBI knew Aoki was arming the Panthers, or was involved in that, it would raise questions about whether the bureau was attempting to foment violence that would discredit the Panthers or set them up for a police crackdown.

The Panthers became a major target of such dirty tricks under the FBI’s unlawful COINTELPRO operation, as Congress later found, but there is no indication in the released records that Aoki was knowingly involved.

Carol Cratty, an FBI spokeswoman in Washington, declined to comment for this story.

The newly disclosed documents provide more information about Aoki’s informing but raise more questions about his true role. Some of his friends have contended that although he began his informing at the behest of the FBI, he eventually became radicalized.

Yet the records show that at least through 1971, he named dozens of people as being members of various activist groups, attending political meetings, giving talks or writing unsigned articles.

According to the documents, Aoki informed on the Black Panther Party; the Asian-American Political Alliance; the Young Socialist Alliance; the Socialist Workers Party; the Red Guard, a radical group in San Francisco’s Chinatown; and the 1969 Third World Liberation Front strike and several other campus political groups at the UC Berkeley.

Seale and Elaine Brown, a former Black Panther chairwoman, and Elbert “Big Man” Howard, another former Black Panther official, did not respond to emails seeking comment. In 2012, after the first story about Aoki’s FBI involvement was published, Seale told a community forum in East Oakland: “This here is a defamation against my friend, my comrade.”

During a 2007 interview, Aoki denied he’d been an informant but added, as if by way of explanation: “People change. It is complex. Layer upon layer.” An additional release of FBI records confirmed that he had been a paid informant for 16 years who used the alias “Richard Ford” in his reports, but the bureau heavily censored those records.

Harvey Dong, a longtime friend and executor of Aoki’s estate, said in an email that based on the partial records released by the FBI over the years, he remained convinced that Aoki had become a true revolutionary by the time he joined the Panthers. “The documents themselves show that he did not fully cooperate with his FBI handlers, with much of the information [he] disclosed in the realm of public knowledge. The documents themselves leave open that he made efforts to side with the movement when sides had to be chosen,” he said in the email.

The FBI in April reprocessed more than 700 pages of those records as the result of a Freedom of Information Act lawsuit filed in 2011. A report on the Panthers, dated Nov. 16, 1967, lists Aoki as “top level” informant SF 2496-S. FBI officials deemed his position extremely sensitive. Had the Panthers known then that he was an informant, he might have been in grave danger.

Aoki also provided intelligence that the FBI used in its security investigation of Seale. In a lengthy report on Seale dated Nov. 30, 1967, Aoki was one of several informants.

According to the report, Aoki told the FBI that as of July 1967, Seale was receiving welfare payments and working full time as chairman of the party. He also reported that Seale and his wife had separated and that she and their infant had moved in with her parents, it said.

Seth Rosenfeld is the author of the book, “Subversives: The FBI’s War on Student Radicals, and Reagan’s Rise to Power.” He previously wrote about Aoki for The Center for Investigative Reporting in 2012. He can be reached at seth@sethrosenfeld.com.