His death has been confirmed by several organisations.
He is widely reported to have died in a traffic accident in Bahrain last week, where he was working for Northern Ireland Co-operation Overseas - a public body which sends advisers to work with public sector bodies in other countries.
Hunter worked for the Police Service of Northern Ireland until 2004, having joined in 2001 when it was known as the Royal Ulster Constabulary. Prior to this police role, he had worked as a press officer and television publicist for the BBC. Before that, he had worked for agency GCAS PR.
On leaving the police, he returned to journalism as editor of the Belfast News Letter.
He also recently worked as a consultant to County Down agency LK Communications.
People and organisations paying tribute to Hunter on Twitter included Deputy First Minister Martin McGuinness, who wrote that he was a "v good journalist & nice man".
We are saddened at the tragic news of Austin Hunter’s death. Our thought are with his family at this very sad time.
— PSNI (@PoliceServiceNI) December 4, 2016
My tribute to ex-News Letter editor Austin Hunter: Charismatic figure who restored a newspaper which he cherished https://t.co/QhI8eq3RUb pic.twitter.com/FMSl5Z4ybZ
— Alistair Bushe (@abushe7) December 5, 2016
Shocked & saddened to hear of death of our dear Austin Hunter ex Head of Press at BBC Belfast & legendary journo. https://t.co/4w0lZoYW3V
— Donald Steel (@LondonDonald) December 4, 2016
Sad to learn of the death of former @BBCRadioFoyle journalist Austin Hunter.A v good journalist & nice man.My sympathy to his wife & family.
— Martin McGuinness (@M_McGuinness_SF) December 4, 2016
Stunned by my friend Austin Hunter's passing. He became a great PR man, but was always a top class journalist at heart who loved the trade.
— Darwin Templeton (@darwintempleton) December 4, 2016