The corporate estate of Martin Luther King Jr.—already enmeshed in a court battle pitting the civil rights leader’s two sons against his daughter Bernice King, the CEO of the King Center for Nonviolent Social Change—has opened a new front in the intra-family dispute over their father’s legacy.

On Friday, attorneys for the estate filed a complaint in Fulton County Superior Court demanding that Bernice King relinquish the Nobel Peace Prize her father won in 1964, and MLK’s “traveling Bible.”