German dancing duo, The Kessler Twins, die aged 89 by 'joint assisted suicide'

German police have opened up an investigation into the death of variety show stars and twin sisters Alice and Ellen Kessler, who shot to fame in the 1950s.

According the the German news agency dpa, the pair were found on Monday in the home they shared in Grünwald, a prosperous suburb of Munich.

They were 89.

In a statement released on Tuesday, Munich police confirmed the deaths, saying it was a "joint suicide" and they have ruled out any third-party involvement.

The twins learned to dance at a young age and joined the Leipzig Opera children's ballet. In 1952, when they were 16, their family fled to West Germany, where they danced in a revue theater in Düsseldorf.

In 1955, the sisters were discovered by the director of the Lido cabaret theater in Paris, where their international career took off. They went on to sing and perform with Fred Astaire, Frank Sinatra and Harry Belafonte among others.

In the 1960s, The Kessler Twins, as they were professionally known, toured worldwide, moved to Rome, and according to dpa, refused an offer to appear with Elvis Presley in 'Viva Las Vegas' in 1964 for fear of becoming defined by musical films in America.

Even at 80, the sisters appeared on stage in a musical. Alice said shortly before their 80th birthday that they probably wouldn't have managed to perform for so long alone.

Being a twosome “only has advantages,” she said. “Together you're stronger.”

Asked about the secret of their success, she remarked: “Discipline, every day. Gratitude, time and again. Humility, not cockiness. And togetherness. Until death.”

Last will and testament

In Germany, assisted dying is permitted in certain cases and under specific conditions. The person must 'act responsibly and of their own free will', as well as be of legal age and have legal capacity.

In their will, the twins had requested that their ashes be kept in the same urn. However their wish is unlikely to be respected as under German burial law, the mixing or combining of the ashes of several deceased persons in one urn is prohibited.

They were given honorary awards from the German and Italian governments for their contributions to the entertainment industry, including the Order of Merit of the Federal Republic of Germany in 1987.