Murphy was arrested by British forces on 15 July 1920 for being in possession of a dud bomb used for throwing practice and was imprisoned in Cork County Gaol.
[10] On 11 August 1920 Murphy joined a large group of prisoners at the gaol on a hunger strike in conjunction with the Lord Mayor of Cork Terence McSwiney.
[12] The 1923 hunger strikes were protests carried out by republicans against the continuation of their internment without trial by the Irish Free State government.
Joe Murphy died after seventy-six days without food on 25 October 1920 and was buried in the republican plot at St. Finbarr's Cemetery, Cork with full military honors.
[14] Joe Murphy is buried next to fellow hunger striker Terence MacSwiney (who also died on 25 October 1920) and the assassinated Lord Mayor of Cork Tomás Mac Curtain.