Assuming that the axles are the same length and the wheels have the same offset with the same size tires, that means that the entire differential housing is offset in the chassis.
The only way for this to happen is if the UCAs are torn off of the floor of the car, or the bushings in one end of them are destroyed, or the bushings at the differential end are pulling out of the ears on the housing. The effective length of the UCAs are what control the lateral position of the housing in the chassis.