After the death of a 24-year-old man at Potsdamer Platz, the Berlin police arrested two men.
Two construction workers aged 22 and 23 were questioned after the incident on Saturday afternoon and then arrested, a police spokesman said.
The murder commission is now assuming that the 24-year-old was killed, but the exact circumstances of the crime are not yet clear.
There are said to have been no other injuries.
According to information from Sunday, the two suspects are currently in custody.
The 24-year-old construction worker was found on Saturday afternoon with severe stab wounds in a lounge in the basement of the Sony Center.
Rescue workers had tried unsuccessfully to resuscitate the man on site.
The dead man belonged to a group of construction workers who were busy with interior work.