A 57-year-old Queensland cyclist has died in a serious crash involving a truck near Nullarbor on South Australia's far west coast.

Key points: Major Crash investigators from Adelaide are examining the incident

Major Crash investigators from Adelaide are examining the incident A major stretch of the Eyre Highway has been closed to traffic in both directions

A major stretch of the Eyre Highway has been closed to traffic in both directions The crash comes less than a week after another involving a cyclist and a truck

The Eyre Highway is expected to be closed for several hours following the incident, which happened just after 9:00am on Christmas day.

The road has been closed by police between Eucla in Western Australia and the Nullarbor Roadhouse.

Police are at the scene, which is about 10 kilometres west of the Nullarbor Roadhouse.

Major Crash Investigation Officers from Adelaide are examining the circumstances surrounding the crash.

It is the second serious accident in South Australia involving a cyclist and a truck in less than a week.

Last week, a 32-year-old truck driver from Albert Park was arrested and charged after a cyclist was killed at nearby Port Adelaide.

The 59-year-old from Kingswood died at the scene, after he was struck at the intersection of the Port River Expressway and Perkins Drive on Thursday.

The previous day, a motorcyclist died after colliding with a truck on Waterloo Corner Road at Burton.

The 31-year-old from Paralowie was rushed to hospital in a critical condition and later died from his injuries.