An elderly man died when he fell from his bike during a "medical episode", police said.
Officers said the 83 year old man, from Preston, collapsed in Sidgreaves Lane in Lea at around 12:15pm yesterday.
A North West Air Ambulance doctor pronounced him dead at the scene.
Now Preston police have launched a public appeal for information.
Sgt Michael Higginson of Lancashire’s Tactical Operations Division, said: “These are tragic circumstances where a man has died after what we suspect is a medical episode.
“Our thoughts are with the gentleman’s family at this incredibly upsetting and difficult time.
“If you were in the area and have any information that could help with our investigation, please get in touch.”
You can call us on 101 quoting log number 527 of 8th August.