Integral of motion in general relativity and the effect of accumulating excessive internal energy of a body under gravitational contraction

We show that under gravitational contraction of a spherical body, its internal energy increases infinitely as the body radius approaches $GM/c^2$, which leads to a negative mass defect and unavoidably to an explosion process with ejection of part of the body mass because the spherical compression is unstable. This conclusion follows exactly from the general theory of relativity in harmonic coordinates.