AceShowbiz - A lawyer for former ABBA star Anni-Frid Lyngstad is threatening to sue the bosses of a martial arts center in Sweden if they fail to return a $6.9 million investment the singer insists was just a loan. The Swedish singer, widely known as Frida, is demanding officials at the Yantorp Qigong resort return the money she handed over several years ago.

Reuss has even suggested the company behind the hotel and temple, which offers traditional Chinese medicine and meditation, be liquidated to allow her to recoup the huge sum. Managers at Yantorp Qigong have been left dumbstruck by the pop star's claims - because they were under the impression the cash injection was a gift.

Temple leader Marcus Bongart says, "It's a shock. We are all very sad. (The money) was anything but a loan. Frida wanted to support us here in our project and the valuable ideas that exist here. She has been a friend for 20 years. We have been conned."

But Reuss' legal representative, Carl-Gustaf Soeder, has warned they will face a court battle if they fail to act on the Waterloo singer's request.