Any insurer who suspends, terminates or decreases payments of compensation without submitting an agreement or supplemental agreement therefor as provided in section 408, or a final receipt as provided in section 434, or without filing a petition and either alleging that the employe has returned to work at his prior or increased earnings or where the petition alleges that the employe has fully recovered and is accompanied by an affidavit of a physician on a form prescribed by the department to that effect which is based upon an examination made within twenty-one days of the filing of the petition or having requested and been granted a supersedeas as provided in this section, shall be subject to penalty as provided in section 435.
77 P.S. § 774.1