The cyclist was killed after colliding with a freight train at a level crossing this morning.
Police say the accident happened at the Fendalton Road crossing shortly after 8am.
The cyclist was riding a mountain bike.
Senior sergeant Anton ten Hove confirmed the deceased is an adult male. He is yet to be identified.
Paramedics worked to save his life but he was pronounced dead at the scene.
It's not yet clear which direction the cyclist had been travelling, Mr ten Hove said, adding that he is yet to speak to the train driver.
"It's obviously a tragedy and I can't yet confirm why it happened but cyclists do need to pay attention to where they are cycling, with critical areas being intersections and railway crossings," he said.
Kiwirail spokeswoman Joanne Black said the train was travelling from Picton to Christchurch when the accident happened.
She said there were barrier arms at the crossing and they were working at the time.
The train driver would be stood down.
Tarpaulins have been erected at the scene around the body.
Coroner Marcus Elliott is at the scene along with many police officers. A hearse is set to take the body away.
A cycle path runs across the intersection. Signs warn, 'Look for trains'.
Cyclists are passing, with many asking what has happened.
"That's a tragedy," one passing cyclist said.
The serious crash unit is investigating.
The road is blocked to traffic and the crossing's barriers are down and warning bells still ringing.
