Four people are feared dead following the collapse of a disused British power station, and another five are seriously injured, emergency services said Wednesday.

One person was confirmed killed when the Didcot A coal and gas-fired power station, owned by a subsidiary of German giant RWE and scheduled for demolition, collapsed on Tuesday in a cloud of dust and rubble.

Rescue workers are searching for three other people who are missing but regional fire and rescue service chief Dave Etheridge, said: "It is highly unlikely they are alive."

Etheridge told reporters that the families had been informed that "we have not picked up any signs of life".

"We have tried their construction site radios and have had no response. We see this as significant," he said.

Prime Minister David Cameron paid tribute to the emergency services in comments in parliament and expressed his condolences to the confirmed victim's family.

Etheridge said sniffer dogs were being used in the search for the missing, adding that the operation "may take several days, possibly several weeks".

Scott Chilton, a senior police officer, described the five people taken to hospital as "seriously injured, but not critical".

Emergency workers said there were no explosives in the 10-floor building at the time of the collapse despite initial reports that it had been preceded by a blast.

About 50 people were treated for dust inhalation at the scene.

Didcot A was opened in 1970 and ceased generation in 2013. Three of its enormous cooling towers were blown up in July 2014.