Martin Ebner, the financier who once struck fear into the Swiss business establishment, has made a comeback by buying a 6.9% stake in Skanditek, a Swedish investment company.

It is understood Ebner's BZ Bank bought part of the stake sold by Johan Björkman, chairman of Skanditek and one of Ebner's friends. Björkman is the former chairman of A-P Fonden 3, one of Sweden's national pension funds. He was sacked last September after refusing to step down while under investigation for insider trading.