The man, who is in his 20s, travelled to Turkey on Tuesday but was stopped at the border.
“We found out that this person left for Turkey and then issued a 'no entry' to border police there who managed to seize him. Hopefully he is to return today and then Swedish police will take care of him,” Dan Windt, head of the southern Gothenburg policing area, told Gothenburg newspaper GP.
Another two men, aged 16 and 21, remained in custody on suspicion of aggravated arson on Wednesday, in connection with a spate of car fires in the area around Gothenburg on Sweden's west coast.
Police and fire services were called out to a number of fires in several Gothenburg districts, as well as in towns further afield on Monday evening. In total around 80 cars burned that night, they said.
A witness told The Local that he had seen half a dozen people torching cars and throwing molotov cocktails in the car park outside his home in Frölunda, a usually calm suburb south of Gothenburg.
“They acted like a team, absolutely. It was organized. They knew exactly what they were going to do,” he said.
Police said they suspected the attacks had been coordinated on social media. The nature of Monday's fires is unusual, with no other clashes or disturbances noted in the run-up to the burnings.
They said they had identified many of the people believed to have been at the scene.
“We will be bringing more people into custody tonight and tomorrow. I think it's around ten youths acting at the same time. These are criminal guys, older teenagers, who live in the area,” Dan Windt, head of policing area Greater Gothenburg South, told the TT news agency on Tuesday.
“We really know in what groups this is happening and are now going to work with crime prevention on the ground,” he added.
READ THE LOCAL'S COVERAGE OF THE CAR FIRES:
- Arson suspects held over car burnings
- Video: Masked thugs torch cars in Swedish suburb
- 'What the hell are you doing?' Politicians react to car fires
Another four cars were set on fire on Tuesday night, two in Västra Frölunda which was one of the worst-hit areas on Monday, one in Mölndal outside Gothenburg and another in nearby Borås.
It is unclear if the incidents are linked to Monday's mass burnings in Trollhättan and Gothenburg.
“It's just one car in each place and feels more random, but it is hard to say if it is the same gang. Unfortunately car fires are not completely uncommon,” control room officer Johan Ljung told TT.
Car burnings tend to spike in August before the start of the school semester, said police.
Between January and July this year 1,835 such fires were registered according to preliminary statistics by the National Council on Crime Prevention (Brå), compared to 2,263 in the same period last year.