Mr Bergholm said: "Police arrived first, then the fire brigade who came with fire brigade divers at the scene and found the car and three bodies.
"We didn't know how many people there were in the car but we found out there were five. Later on, about an hour later, the police divers came and found two more bodies."
The men were all identified using their passports they had on them and Swedish police are working with the Foreign Office global response centre.
A foreign office spokesman said: “We can confirm that five British Nationals died in a car accident in Sweden on 13 February.
“We are in contact with local authorities and supporting the families at this difficult time.”
The band were due to support Blossoms at a concert at the Boiler Room in Guildford in Surrey last night, but the gig was cancelled.
Tributes have to the band, from Warrington in Cheshire, have since poured in on social media.
Tim Marshall wrote: "Just heard the awful news about @viola_beach, love their music, didn't know them but knew @craigtarry, RIP big man and the rest of you lads."
Fellow British band The Enemy wrote: "RIP Viola Beach and their manager. Such incredibly tragic and sad news. Thought with the friends and families of all involved x."
And Alex Myles tweeted: "R.I.P to all members of Viola Beach, such terrible news."