Dolphins' deaths blamed on heroin substitute

May 7, 2012 8:59:44 PM PDT
Toxicology tests blame the deaths of two dolphins at a Swiss zoo on someone giving the marine mammals a heroin substitute.

The dolphins died in November after the zoo hosted a large rave party for thousands of people.

The toxicology report was recently leaked to the Swiss media. Prosecutors originally rejected the idea that someone tossed drugs into the dolphins' training pool during the rave.