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.
Food will not be exempt from GST in Guernsey
Deputies have voted through the concept of GST at 5% on food shopping - but were reminded the final vote is not until the summer.
"We want our schools to be smartphone-free environments"
The impact smartphones have on the Bailiwick's youngsters is going to be studied.
Assisted dying will be offered in Jersey
An assisted dying service will be offered in Jersey to terminally-ill adult residents in unbearable suffering who have less than six months to live.
Guernsey Man (23) jailed for abusing teen girl
A man who sexually touched a girl almost a decade younger than him has been handed a jail sentence.
New Guernsey charity to fund gender-affirming items
A new charity has been set up to help transgender, non-binary, and gender-non-conforming islanders access clothes and accessories that boost confidence and happiness.
Bank tax receipts boost the States of Guernsey's fortunes
Public finances have been delivered a £36M windfall but with a warning that it cannot be counted on regularly.
'Multi-generational' living could ease Guernsey's housing crisis
The Planning Authority says homeowners considering an extension for a family member could be helped by an existing policy.
Guernsey dance school upset by temporary theatre closure
A Guernsey dance school says its summer show could be cancelled after Beau Sejour Theatre announced a two-month closure.
