Micky Dolenz is taking his search for answers from the FBI into a courtroom with a new lawsuit, Rolling Stone reports. The last remaining member of The Monkees filed a lawsuit against the FBI over the agency’s failure to hand over a previously classified file.

The document in question dates back to the era of J. Edgar Hoover‘s G-Men infiltrating the counterculture of the 1960s, a simpler time when one of the greatest threats to the American establishment was shaggy-haired rock n’ rollers. During this period, the FBI dispatched an undercover agent to a Monkees concert on the band’s 1967 inaugural tour to report on the rumblings of the psychedelic underground that continued to grow increasingly dissatisfied with the Vietnam War.

“During the concert, subliminal messages were depicted on the screen which, in the opinion of [informant’s name redacted], constituted ‘left wing intervention of a political nature,’” reads a document in the Monkees FBI file. “These messages and pictures were flashed of riots, in Berkley, anti-U.S. messages on the war in Vietnam, racial riots in Selma, Alabama, and similar messages which had unfavorable response[s] from the audience.”

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The lawsuit was filed on Dolenz’s behalf by lawyer Mark S. Zaid, a lifelong fan who received a stack of Monkees albums from his babysitter in 1975. Zaid went on to represent the government whistleblower in former President Donald Trump‘s 2019 Ukraine scandal, which set the stage for his first impeachment. Zaid met Dolenz not long ago and suggested he file a Freedom Of Information Act request to obtain any FBI files on him and his late bandmates Davy Jones, Peter Tork, and Michael Nesmith. It turns out that a seven-page portion of the file—including the intel on the 1967 concert—was released in 2011.

“That just kind of reinforced for me that there was actually something here,” Zaid said. “It’s not just a fishing expedition. I mean, we’re still fishing, but we know there’s fish in the water.”

Legally, the FBI is required to respond to FOIA requests within 20 days. Due to the sheer volume of requests as well as the pandemic and the January 6th investigation, however, that has not lately been the case . The seven pages (available to read on Rolling Stone) released in 2011 were heavily redacted, and also refer to a second document redacted entirely. While the notion of blotted-out, confidential FBI files conjures up grand ideas of intrigue, Zaid even admits that the concealed information is likely mundane.

“The redacted information may be peripheral to them,” he said. “Some of them likely reflect an informant’s identity, which was probably the person attending the concerts.”