the niobe mural has been seized from bilal khaled , accused of buying the work painted on a door belonging to the darduna family without telling them its real value .
the now homeless family in the impoverished islamist-run palestinian enclave says they were ` tricked ' into parting with the valuable collector 's item by the world famous street artist .
it is now being held at khan yunis public library , who chooses to remain anonymous , released an online video showing three works he painted on the walls of gaza that was blasted in a summer war last year between israel and the hamas movement .