I found a comment on a [redacted] site where the commenter is claiming to be Emil's younger brother and that his body was found in Gdansk, Poland on a construction site for a stadium a year after he was murdered. DNA confirmed it was him. There was also another body found in the same grave. The comment also mentions a water pipe and stab wounds as a COD.
I tried to google about bodies found in Poland and I found
an article in polish about a mummified body found in Letnica, Gdansk on a construction site for a stadium (PGE Arena) in a water canal in May of 2010. The autopsy determined the body belonged to a man in his late thirties, however the state of the body was so bad they could not tell if it was a man or woman initially. It's possible they were wrong about the age.
Another article, posted in February of 2012, gives more info and a reconstruction image. They put the age as more or less 33, he was 180-185 cm tall and that he had long shoulder length hair. They believe he died in fall or winter of 2009.
Another article, says his teeth were in perfect condition.
I can't find anything about him being identified though, but it does seem like this was him.