A process for treating a gas stream comprising hydrogen sulphide, the process comprising the steps of: (i) mixing a first gas stream comprising hydrogen sulphide with a second stream comprising sulphur dioxide to produce a combined stream, whereby elemental sulphur is produced by a reaction between the hydrogen sulphide and the sulphur dioxide; (ii) removing elemental sulphur, and optionally water, from the combined stream; and (iii) oxidizing at least some of the elemental sulphur to form sulphur dioxide for use in the second stream, wherein, the reaction is conducted at a temperature of from 15 to 155° C. and a pressure of at least 3 MPa.