The degree to which the footage of Jihadi John has been edited or superimposed will fuel speculation that Isil may be exaggerating his role in the hostage murders for propaganda purposes. Some reports have claimed that he may even have been already killed or badly wounded during a US airstrike in the western Iraqi city of Qaim last month. However, Mr Winter said: "It would be jumping to conclusions to assume that he has been killed or injured simply because some of the recent footage of him may have been edited."