Read More…. string added to excerpt

The moment I have excerpt=’true’ not only the excerpt is shown in the list, but a string consisting of the word ‘Weiterlesen’ (read more) and the event title is added. This text is just ‘dead text’ – no hyperlink and cannot be removed via CSS because it is just part of the excerpt string.
Help to get rid of this annoyance (or a possible bugfix) are highly appreciated.