The New South Wales holiday road toll has climbed to nine after the death of a 21-year-old cyclist, fatally injured at Mullumbimby on December 16.

Daniel Afflick was knocked off his bicycle by a Toyota sedan as he rode east along Mullumbimby Road, Mullumbimby, at 8.15pm on Thursday, 16 December.

Daniel was rushed to the Tweed Heads Hospital and then transferred to the Gold Coast Hospital for emergency treatment to critical head injuries.

Police have confirmed that Daniel was not wearing a bicycle helmet at the time of the crash.

Queensland authorities have informed New South Wales Police that Daniel died from his injuries on Christmas Eve.

Police are reminding motorists and cyclists to show extreme caution on the roads, particularly over the Christmas-New Year break.

Roads across the State are being patrolled by police during Operation Safe Arrival and double demerit points remain in effect for all speeding and seatbelt offences until 2359 hours on Sunday 4 January.