Whenever any civil proceeding shall be commenced by the state to prevent, restrain or punish a violation of this article, the running of the statute of limitations in respect of every private right of action arising under this article and based in whole or in part on any matter complained of in said proceeding shall be suspended during the pendency thereof and for one year thereafter: Provided, That whenever the running of the statute of limitations in respect of a cause of action arising under section eight shall be suspended hereunder, any action to enforce such cause of action shall be forever barred unless commenced either within the period of suspension or within four years after the cause of action accrued, whichever is later.