Police say the man, who's not yet been named, died at around 6.40pm on 18 September.
Police say the 66-year-old died in a single vehicle accident on the track to Fort Clonque, at Alderney's south-western tip.
They say as investigations are carried out there will be a police presence in the area and ask people to stay away.
Healthy heart initiative launches at Guernsey Library
Islanders interested in monitoring their blood pressure can now borrow monitors from the Guille-Allès Library.
Group to examine the complaints process of Guernsey's health service
The views of Guernsey patients and healthcare staff on the current health service complaints process will help shape recommendations for improvement.
Dornier aircraft lands in Guernsey for the final time
The planes have served the islands for more than 10 years, making 32,000 take-offs and landings.
£130,000 needed to treat Guernsey toddler's brain injury
A Guernsey family say they are in a race against time to get stem cell therapy for their toddler, who suffered a brain injury at birth.
Channel Island pooches compete for Dog of the Year title
Top dogs from both Guernsey and Jersey are competing for the ultimate regional honours – celebrating excellence across all breeds and dog sports.
Guernsey homelessness charity supports more than 125 people in first year
At Home in Guernsey has called 2025 "a powerful first full year".
Guernsey Pancake Day fundraiser cancelled
There will be no pancakes served from Town Church on Pancake Day.
American descendants encouraged to visit Guernsey
Residents of Guernsey County, Ohio, are being encouraged to reconnect with their Channel Island roots.
