German police are looking into the possibility that the two people who jumped to their death out of a burning high-rise building in the capital were responsible for starting the fire.

The pair "jumped out of the window very, very quickly” from an apartment in a building in Berlin on Friday trying to escape a fire, the fire department had said.

They died at the scene despite efforts to revive them, fire service spokesperson James Klein said. 

On Saturday, the German DPA news agency cited a police spokesman as saying the 45-year-old man and the 22-year-old woman were suspected of having started the fire. 

The spokesman added that the investigation remained in its early stages.

Another person was slightly injured but rescued via a staircase.

'Very strong heat'

The fire broke out on the 12th floor of a 15-storey apartment block in Berlin-Kreuzberg.

As emergency responders arrived the two people were still alive and reportedly called for help.

A witness who lives on the first floor of the building recounted the incident and said that the woman jumped first, and the man had initially clung to the balcony.

But he let go before the firefighters could fully open the safety air cushion meant to catch him. 

"It takes a lot that you actually jump from a twelve-storey building. There was probably already a very strong heat from behind." Klein said.

Firefighters tried to resuscitate them following their fall but they died on the scene. 

It is not yet clear what caused the fire.

ara/lo (dpa, AP, Reuters)