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.
Channel Islander abandons Bordeaux as the flames 'arrive at the city's gates'
Officials in the Gironde region have told tourists to stay away and are considering evacuating the city of Bordeaux as the flames 'arrive at the city's gates'.
Annual Guernsey Scarecrow Festival set to raise thousands for charity
£10,000 was donated to five Guernsey charities and organisers hope for a similar amount this weekend.
Channel Islands face 'physical' Poland test
The Channel Islands rugby team play their second ever game this weekend - and this time in Jersey.
Baby born on Guernsey's Marine Ambulance
During an emergency transfer from Sark to Guernsey, Harriet Magell was born.
New interim leader for Guernsey's healthcare system
Teresa Cope has senior management experience in the NHS and has recently led the Isle of Man's care system.
Guernsey's reservoir levels falling after prolonged dry spell
Water storage takes a multi-million-litre hit after successive heatwaves.
Guernsey's Commonwealth flag carrier in early Games win
Guernsey bowlers Alison Merrien and Rose Ogier have won their first match in the women's pairs in Glasgow.
Abundant year for jellyfish in Guernsey waters
Social media lights up with pictures of compass jellyfish, but they are relatively common in the summer.
