The tram driver was heard briefly at the hospital yesterday, says the police's press spokesperson Christian Brattgård.
He does not want to go into detail about what emerged during the initial interrogation.
Eight people were injured in the accident. They were taken to hospital, two of them with serious injuries.
Three people are still being cared for at the hospital, a woman in her 20s and two men, 35 and 40 years old. The condition of all of them is stable, says Patrik Centerwall at Sahlgrenska hospital's press service to TT at lunchtime on Saturday.
The accident occurred at the intersection of Vasagatan/Avenyn just before 1 o'clock, on the night before Midsummer Eve. After the derailment, the tram continued on the sidewalk before colliding with the street kitchen, which was completely destroyed.
The work of investigating the accident will gain new momentum after the weekend. We will hear new witnesses after the weekend, if needed. Then we will also continue to look at the surveillance cameras that exist, says Christian Brattgård.
According to information to SVT the Swedish Accident Investigation Authority is to visit the scene of the accident on Midsummer Day to see if the incident should be investigated.
This is a serious incident and that's why we're going to Gothenburg to gather the facts we need to make a good decision, says accident investigator Mikael Hillbo to SVT.
Corrected: In an earlier version, incorrect information was given about the Accident Investigation Authority's visit. The correct information is that the Accident Investigation Authority will visit the scene to investigate whether an investigation should be initiated.
