What is the evidence that happened?
If you're interested in evidence that these are the accusations, see e.g. https://timesofindia.indiatimes.com/world/us/Sex-accusers-bo... or https://en.wikipedia.org/wiki/Assange_v_Swedish_Prosecution_... or https://www.theguardian.com/media/2010/dec/17/julian-assange... or http://www.abc.net.au/news/2016-11-14/julian-assange-to-be-i... or really a Google search for 'assange condom'.
Some Swedish prosecutors, rather. The accusations were originally dropped, then picked back up by a more politically-oriented prosecutor. It was very, very iffy from the start.
https://www.aklagare.se/contentassets/cc904ed99288454586d860...