Spencer Elden claimed last year he'd suffered "lifelong damages" and "emotional distress" after being featured on the cover of Nevermind as a baby.
The Foo Fighters star said he has "many ideas" about how to resolve the issue.
Spencer Elden was four months old when he was photographed swimming nude for the grunge group's album artwork.
People who wrote to the agency were told an investigation of his death, which had been ruled a suicide, was outside the FBI's jurisdiction.
The Nirvana frontman was only 27-years-old when he died by suicide at his home on 5 April 1994. His band had become the symbol for the so-called Generation X within only a few years of breaking onto the Seattle grunge scene. Nirvana's second album, "Nevermind", propelled them to fame, thanks to hits like "Smells Like Teen Spirit". Cobain, who lived with depression, was reportedly not always comfortable with the levels of stardom he had attained.
We can't wait to hear the band and singers get to grips with this.