Whoever voluntarily causes grievous hurt for the purpose of extorting from the sufferer or from any person interested in the sufferer any property or valuable security, or of constraining the sufferer or any person interested in such sufferer to do anything that is illegal or which may facilitate the commission of an offence, shall be punished with 1[imprisonment for life], or imprisonment of either description for a term which may extend to ten years, and shall also be liable to fine.