We investigated the transformation of magnetic fields and plasma in heterogeneous magnetospheres of collapsing stars with initial dipole magnetic fields and a certain initial energy distribution of charged particles in a magnetosphere (the power-series, relativistic Maxwell, and Boltzmann distributions). The betatron mechanism for the particle acceleration in heterogeneous magnetospheres of collapsing stars is considered. As the magnetosphere of a star is compressed under the collapse, the magnetic field of the star grows considerably. This variable magnetic field generates the cyclic electric field. It follows from our calculations that the electric field will accelerate charged particles to relativistic energy. Thus collapsing stars can be sources of high-energy cosmic rays both in our Galaxy and in other galaxies. The particle acceleration takes place mainly in the magnetosphere polar caps, which results in the generation of polar relativistic jets. Moving in magnetic fields, these particles will generate the nonthermal electromagnetic radiation over a wide range of wave lengths, from radio waves to gamma-radiation. Hence, relativistic jets are formed in the magnetospheres of collapsing stars and can be powerful sources of nonthermal electromagnetic radiation.