Neutral Milk Hotel bassist Julian Koster has been accused of grooming and sexually assaulting a woman when she was in her teens.

In a series of Instagram posts starting July 9, Anna "Nesey" Gallons, musician and member of the Elephant 6 Collective, alleged that Koster began grooming her in 2000 when she was 15 and he was in his late 20s.

Koster denied the allegations Thursday in a statement posted on the Instagram account for his podcast and musical/performance art group, @orbitinghumancircus.

"I have been the victim of intimidation, manipulation, and abuse by Nesey Gallons for many years," he wrote, adding that the musician's statements "are part of a campaign against me."

USA TODAY reached out to contacts for both Gallons and Koster for comment.

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Nesey Gallons alleges relationship with Julian Koster 'became sexual' when she was 16

"I began to communicate by telephone and correspond via email with Julian Koster routinely in early Y2K at age 15, each exchange gradually becoming more intimate, though seemingly innocent," Gallons wrote. "He imparted the notion that our connection was like none he had ever known."

Gallons alleges they entered a "sexual relationship" less than a year later in April 2001, six weeks before her seventeenth birthday. 

"This, by all common definitions, constitutes 'grooming,'" she wrote.

Gallons also alleged Koster sexually assaulted her twice in the summer of 2005 and that she did not speak up for many years because they remained close friends.

Julian Koster says relationship was 'consensual,' denies allegations

On Thursday, Koster denied the grooming and sexual assault allegations and wrote on Instagram that Gallons' "campaign" against him is documented in "thousands of disturbing, abusive, and obsessive messages."

Koster added that he and Gallons allegedly "entered a consensual relationship in 2001, which continued until 2008."

"When the relationship began I was 28 and Nesey was 16, just before her 17th birthday," Koster continued. "Though this put her over Georgia's legal age of consent when our relationship began, it was wrong to allow the relationship to happen at all and I've apologized to Nesey many times for that. I should have been more responsible about the age gap, but I deny all the other accusations she's made."

Nesey Gallons says being 'psychologically and emotionally manipulated' stopped her from reporting Julian Koster

In her posts, Gallons wrote that being "groomed, assaulted, and psychologically and emotionally manipulated" led her to avoid reporting Koster.

"I felt compelled to protect my friends in the (Elephant 6) community and our fans, holding to that until 2020 when the first utterances of this story escaped my shattered lips in any capacity that named names, and was quickly silenced once I was approached with the possibility of reconciliation, and then erased by his eager PR team," Gallons wrote.

She said "others close to him," including "actual adults," could have reported him and his actions, specifically calling out Neutral Milk Hotel's founder Jeff Mangum.

Gallons concluded by writing that "the point of this is to find peace and move on."

Julian Koster accuses Nesey Gallons and her husband of 'disturbing behavior'

Koster wrote in his statement, "Anyone who knows me now or knew me then understands that I always try with all my heart to approach people with empathy and love, including Nesey, and over the last few years I’ve been working hard to build a friendship and to listen to her and acknowledge the pain that she feels.

"My efforts have been met with increasingly disturbing behavior on the part of both Nesey and (spouse Paul Gallons), including thousands of threatening and manipulative messages, which are meant to punish me for not agreeing to what they want."

Koster claims Gallons and her partner have "demanded" the bassist "be in a romantic relationship with them, marry Nesey, move in with them away from my friends and family, finance their living expenses, and let them control me, emotionally, physically and sexually."

Gallons and her husband have not responded to Koster's claims.

Koster concluded by saying that he will "no longer be able to tolerate being abused and controlled" and is seeking an order of protection from them both.