Her final text contained just a single word, but it haunts Jean Hanlon's (pictured) family to this day. 'Help', the message read.

Assault charges against a north Queensland teenager have been upgraded to murder after the alleged victim died following a two-month stay in hospital.

Police said the 17-year-old Townsville boy assaulted a 63-year-old man in Innisfail in April.

The man suffered serious head and facial injuries and was taken to hospital in critical condition.

Assault charges against a 17-year-old Townsville boy have been upgraded to murder after the alleged victim, a 63-year-old man, died following a two-month stay in hospital (stock image)

Assault charges against a 17-year-old Townsville boy have been upgraded to murder after the alleged victim, a 63-year-old man, died following a two-month stay in hospital (stock image)

Assault charges against a 17-year-old Townsville boy have been upgraded to murder after the alleged victim, a 63-year-old man, died following a two-month stay in hospital (stock image)

He died on June 25, two months after the alleged assault.

The teen’s initial charge of causing grievous bodily harm was upgraded to murder.

The 17-year-old is due to appear at Innisfail Children’s Court at a later date.

Investigations into the incident continue.