What should be done with money bequeathed from a provident fund?

If one had contributed money to the provident fund, then it is only permissible for one to take back the amount one had contributed. The extra amount is riba (interest) and should be given away to the poor in charity without the intention of receiving any reward. Similarly one should make taubah for getting involved in the sin of interest.

And Allah Ta'ala (الله تعالى) knows best.