We consider a system of differential equations describing the rotational mo
tion of a rigid body whose center of mass moves in a circular orbit. The ai
m is to prove its nonintegrability. For this purpose we apply Ziglin theore
m about nonintegrability of Hamiltonian systems. In the system studied the
assumptions of this theorem can be checked numerically. We describe a numer
ical technique adequate for this purpose. Using it we obtain a 'numerical p
roof' that the system is not integrable.