Bonn, Germany  - German mail carrier Deutsche Post, which offers customized postage stamps as an unusual gift, admitted Wednesday that it had been tricked into issuing 20 Nazi stamps.

The stamps depicted Rudolf Hess, the deputy to Nazi dictator Adolf Hitler. Hess, who committed suicide in Berlin in 1987 while serving a life sentence for war crimes, is venerated by neo-Nazis.

Post launched the novel service, Plusbrief Individuell, in February. Clients pay online to upload a digital photograph of a loved one or of a commercial product. A week later, they receive printed, post-paid envelopes showing the same picture.

Neo-Nazis apparently exploited the opportunity and Post staff did not notice.

"It was a slip-up. We are very sorry about it," said Post spokesman Dirk Klasen at the company's offices in Bonn. (dpa)