It has been observed that `runaway oscillations' in the toroidal current ofthe magnetized resistive toroidal plasma may cause continuous tearingactivity, resulting in `spiky' net toroidal current and modulation of toroidaland poloidal magnetic fields of the plasma with a definite phase relationship,depending upon the magnitude of vertical magnetic field. The presentexperimental results on current decay and recovery are explained fromthe point of view of helicity conservation.