Unconfirmed reports circulating on Twitter state the Islamic States spokesperson, featured heavily in a recent Vice News documentary, has been killed by the Syrian Army.

News of Abu Mosa’s death broke earlier this morning, however there has been no confirmation of the spokesperson’s demise.

Mr Mosa was recorded by Vice News as part of their documentary inside the Islamic State.

The documentary has been widely viewed, thanks to the unprecedented access gained by Vice reporter Medyan Dairieh, who is seen in the released footage reporting openly in Raqqa, Syria.

Video: Isis warning to the West

A pro-Isis Twitter accounts said: "This brother Abu Moussa was martyred during missile clashes" by the Syrian Arab Army in Taqba airbase in Raqqa, with a still from the Vice News documentary of Mr Mosa.

Much of the film released features Mr Mosa, who as a spokesperson for the Islamic State, said: “I say to America the Islamic Caliphate has been established and we will not stop”.