six-bedroom brothel in melbourne 's fitzroy will go up for auction on may 1 .
edwardian-style shopfront was owned by wei tang who was jailed for keeping five thai women as sex slaves .
property , formerly known as club 417 , comes with a brothel licence .
tang was convicted in 2006 for forcing women to work off debts incurred by bringing them from thailand to australia .
it stopped operating as a brothel in 2013 and has been vacant ever since .