  The 2+1 black hole anti de Sitter solution, obtained as a special limit of
the conformally exact $SL(2,R)\otimes SO(1,1)/SO(1,1)$ coset WZW model to all
orders in 1/k, is investigated with respect to tachyon scattering. We calculate
the off-shell reflection and transmission coefficients and we find an
expression for the Hawking temperature, which in a certain limit reduces to the
statistical result.
