Sergeant Gary Locker said officers were having to carry bodies over their shoulders in places to bring them from the site of the explosion to Russell Square Tube station, 600 metres away.
A total of 21 bodies have been recovered so far from the mangled remains of the bombed carriage, in a task described as one of "extraordinary horror".
Sgt Locker, who worked on the Selby and Ladbroke Grove train crashes, as well the Asian tsunami, said: "The mantra is search, find and photograph."
Senior officers have said the work is incredibly hard because of the heat, rats, and risk of exposure to asbestos and dust. "Because of the heat and conditions they can only work there for two hours at a time," Sgt Locker said.
The two-strong teams of recovery officers travel to the blast site on a motorised trolley that has been specially installed.
They are dressed in protective suits, boots, gloves, hard hats, and masks and communicate with their colleagues on the station via radio.
Their tasks are to remove bodies and search for any evidence, such as bomb fragments and remains of any timing device.
Cutting equipment is used to free any bodies trapped in the twisted remains of the carriage.
"Bodies sometimes have to be carried on the officers' shoulders and placed in bags," said Sgt Locker. "They photograph and video everything before they move it," he added.
Once the recovery teams have completed their two-hour shift they go to a decontamination cabin where their suits are washed down.
Deputy Chief Constable Andy Trotter, of British Transport Police, said rescue teams were continuing to work long hours in very difficult, hot conditions.
"A number of bodies have been recovered from the train and taken to the mortuary, but they are continuing to work down the train looking for any other bodies trapped underneath This is a slow, painstaking and methodical task.
"They are working their way towards the back of the train, where they're going to continue to search for bodies and forensic material."
Sir Ian Blair, the Commissioner of the Metropolitan Police, described the officers' task as "a very long job, and a job of extraordinary horror".Reuse content