Benzos are increasingly implicated in drug related deaths. In particular when used in combinations of other substances. Fake benzos are often sold on the street, between friends and dealers. Nobody actually knows what is in these tablets, how strong or how dangerous.
There is a statement from the national Drug Death Taskforce on Benzodiazepines - here
This is a really helpful leaflet produced by CREW - here
This factsheet can help if you suspect a Benzo overdose