Dolly Parton's Manager Accuses Singer's Nephew of Violent Threats, 'I'm a Killer'

Dolly Parton's family war is getting ugly ... with her longtime manager filing a lawsuit seeking a temporary restraining order against the late singer's nephew, Bryan Seaver, TMZ has learned. 

TMZ obtained court docs filed by Dolly's manager, Danny Nozell. The manager claims Bryan began "invoking his self-proclaimed military-contractor experience, access to weapons, and capacity for violence" to extort Dolly's manager into giving in to his demands for money. 

The manager said he was forced to terminate Bryan due to his threatening conduct ... and said he started a campaign of threats, intimidation, and coercion a few weeks before her passing. 

One alleged threat read, "Her money better be bigger than I can make elsewhere or I'm going to f*** everyone. I am about to become the hand of retribution for my entire family."

Another alleged threat sent by Bryan read, "I’m going to set up a podcast dedicated to ruining Dolly's brand partnership and telling the violations these people have done on us."

Another alleged message read, "All I do is warfare ... everyone needs to be worried about what I might do." Seaver also allegedly wrote "I'm not an entertainment person. I'm a killer" and "I'm going to ratf**k every entity I can possibly conjure" in messages submitted as exhibits.

The manager terminated Bryan on September 15. His lawsuit is asking for Bryan to not interfere with Dolly's business and leave their business partners alone ... and stay 1,000 feet away from the offices.

As TMZ first reported, Seaver was recently kicked off her properties after working as her head of security for years. 

Bryan denies the claims in the petition. He tells TMZ ... "I am a career soldier and military contractor and do conduct arms deals for foreign governments. I am a security professional and I am a killer."

He added, "However, nothing in this lawsuit were threats and most of the comments I stand by." Bryan said the messages were taken out of context to make it look like he was threatening people.

"I was talking frankly in a private way with Danny who I thought was my friend and he fancies himself a gangster," he said. "A lot of these messages are two guys having rage talk and crying on the phone together while we were grieving."

In regard to the "rat f**k" comment, Bryan tells us "I was talking about people that have done bad to Dolly in business – a specific company that scared her and intimated her. Those comments were about specific, horrible business partners that have done wrong to her and I stand by that."