NASUM singer/guitarist Mieszko Talarczyk is among the 800 Swedes still missing in Thailand following the massive undersea earthquake measuring 8.7 on the Richter scale and resulting tsunamis along South Asia's coasts.
The latest estimates are that over 23,000 have perished in the region.
The remaining members of NASUM have posted the following message on their web site:
"It's very hard for us to make this announcement, but since rumours are already out on the Internet we must make an official statement: Mieszko Talarczyk is missing in Thailand.
"Mieszko and his girlfriend went to Thailand to spend the holidays. They left a few days before Christmas and were scheduled to return right after New Year's Eve.
"They were staying in a bungalow at Phi Phi Island and when the big wave came and swept the bungalow away the two were separated. Mieszko's girlfriend is being reported hospitalized 'badly injured' but she has been in contact with among others Mieszko's sister who has been posting an 'I'm looking for...' at the Phuket Disaster Forum.
"This is everything we know right now. Since we are all shocked by this surreal situation we strongly advise fans of NASUM to respect the anxiety we and the Talarczyk and Thorén families feel at this time, and NOT post questions by email or in the guestbook at Nasum.com. We will post all sorts of news on the website, but again, please respect our wish in this uneasy time.
"Sincerely, Anders, Jon and Urban of NASUM."
The Swedish Foreign ministry confirmed that two Swedes are among the dead in Thailand, according to ChinaView.cn. The pan-Nordic SOS emergency center in Copenhagen reported that seven Swedes died.
One Swedish newspaper, Expressen, quoted a foreign ministry source as saying that "between 20 and 50" Swedes were feared dead, but this could not be confirmed.
Hundreds of Scandinavians are reported to have injuries ranging from light cuts and abrasions to those in critical condition.
Some 800 Swedes are still unaccounted for on the island of Phuket in Thailand, a popular holiday destination.
Swedish tour operators which had flown some 1,100 Swedes into the Khao Lak resort north of Phuket, said they have information on the whereabouts of only around 400 holidaymakers.
The Swedish embassy in Thailand has set up a provisionally crisis center in Phuket to help Swedes in the area, according to ChinaView.cn.
The Swedish church in Bangkok is also organizing care for Swedes in Thailand.
Sweden's ambassador to Thailand, Jonas Hafstroem, said that he was "shaken" after visiting injured Swedes in hospital and "feared that many had died", but said it was too early to say how many.
Up to 15,000 to 20,000 Swedes could have been holidaying in the vast region affected by the floods over Christmas, he said.