As an actor, O'Neill was best known for playing the character Hugh in Season 6 and 7 of the motorcycle club TV drama Sons of Anarchy, but the actor's career dates back to the 90s.
Actor Timothy V. Murphy wrote: "My good friend Alan O'Neill died today...we worked together on The Sons Of Anarchy...my condolences to his family".
The actor's manager Grey Meyer confirmed O'Neill's death after reports emerged that he had been found dead in his apartment in Los Angeles on Wednesday night.
The publication also claimed the Sons of Anarchy star suffered from heart problems and was a heavy smoker.
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An autopsy will be carried out but his death is not being treated as suspicious according to TMZ. He also played the regular role of Keith McGrath in drama series Fair City - set in the town of Carrigstown - from 2006 to 2012. He later moved on to small screen roles like Inspector George Gently in the Irish series Fair City from 1989 to 1994. He was most recently seen in 2016's Urge. So very sorry to hear of your passing.
"My thoughts and prayers to you and to your family".
"Always enjoyed working with him".
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