The bouncer was arrested after witnesses said that he had been heavily involved involved in a violent fracas outside the fashionable night spot.
“He was identified by several witnesses as having beaten a person and kicked them in the head. That person is very seriously injured,” police spokeswoman Ann-Charlotte Wejnäs told the TT news agency.
The same bouncer is also thought to have assaulted at least one more customer.
“There is often a reason why security guards remove guests and we are trying to find out more about that. There are a lot of witnesses, which we are grateful for,” said Wejnäs.
According to the police spokeswoman, the row started when one of the guests who had been asked to leave demanded to go back in to retrieve an item of clothing.
A total of seven or eight people are thought to have been involved in the fight.