NEW : Israel police chief `` 99 percent '' sure French intel unit is behind Hamas slaying . Dubai says only media reports link it to killing and there 's no reason to blame Mossad . Leading Hamas figure found dead in his Dubai hotel on 1989 . Toxicology report found significant amounts of a drug used to relax muscles .
NEW : Dubai police chief `` 100 percent '' sure Israeli intel unit is behind Hamas slaying . Israel says only media reports link it to killing and there 's no reason to blame Mossad . Leading Hamas figure found dead in his Dubai hotel on January 20 . Toxicology report found significant amounts of a drug used to relax muscles .