The singer, real name Robert Velline, lost his battle with Alzheimer's disease in October (16), aged 73, and less than four months after his passing, his heirs have become embroiled in a legal dispute.

According to Minnesota's St. Cloud Times, Robby Velline and his sister Jennifer Whittet Velline have filed a petition in Stearns County District Court accusing their brothers, Tommy and Jeff Velline, of using estate funds for their personal benefit. They also allege the siblings have taken money to support Rockhouse Productions, a studio founded by their dad and their late mother, Karen, who died in 2015.

Tommy and Jeff, who currently run the recording company, have fired back at the allegations, insisting they have done nothing wrong, claiming their use of the funds had previously been approved by their parents.

Their attorney, Troy Poetz, tells the outlet the situation is "painful and sensitive", and, as a result, he has declined to comment on the specifics of the legal action.

All four kids are equal beneficiaries in Bobby's estate, and are listed as trustees for a fund intended to benefit the star's children and grandchildren.