According to Kevin Federline, the father of Britney Spears abused their 13-year-old son. Jamie Spears allegedly had a fight last month with grandson Sean and grabbed the boy roughly.

According to TMZ, the teenager was not injured, but the police are investigating the incident. Agents would have talked to witnesses to determine if they could make a case of the alleged mistreatment.

Kevin already filed the declaration on 25 August. The paperwork came to light when Tuesday it was announced that the singer and her former background dancer had a new guardianship arrangement recorded. Where previously they each spent half the time with their two sons, since this summer they have been living 70 percent of the time with their father and the rest with their mother.

Besides Sean, Britney and Kevin are also parents of Jayden (12).