The present invention provides a process for the recovery of radiolabelled isotopes from organic substances labelled or contaminated with one or more radiolabelled isotopes, which process comprises: i) adding organic substances labelled or contaminated with a radiolabelled isotope to an acidic aqueous electrolyte containing silver ions as an electrochemically regenerable primary oxidising species; ii) subjecting the acidic aqueous electrolyte to an electric potential; and iii) recovering the radiolabelled isotope from the products of the electrochemical process resulting from the application of the electric potential; wherein the process is carried out at a slight pressure depression.