Two quizzed as blaze wrecks landmark Victorian pier
Sussex Police said two males were arrested and were being quizzed about the cause of the fire. The pier has been closed since 2006.
More than 60 firefighters with eight engines were trying to extinguish the blaze, East Sussex Fire and Rescue Service said.
Emergency services were alerted to the fire by a member of the public at 1am.
A spokesman for East Sussex Fire and Rescue Service, Simon Rose, said: "It's still a major blaze. There's about 60 firefighters dealing with the blaze.
"At the moment about 95 per cent of the structure has been destroyed. It's quite significant."
There were no reports of any injuries.
Campaigners in Hastings were trying to raise money to see the pier refurbished with modern attractions.
The council said it was prepared to buy it by compulsory purchase after a study this summer showed it could be made safe for 3 million.
But landlord Dale Turner, who runs the Seaspray bed and breakfast opposite the pier, attacked authorities for failing to secure its safety in time.
"This is the sort of thing people were worried about," the 55-year-old said. "The pier had been allowed to fall into ruin and now we may never get it back."
The pier was owned by Panamanian-registered company Ravenclaw.
It is the latest of a string of historic piers to be hit by fire.
In July 2008, Weston-super-Mare pier was destroyed, while Brighton, on the East Sussex coast, experienced a devastating year in 2003.
In October 2005, a blaze caused major damage to the pier at Southend in Essex, leading to the closure of part of it for 10 months.