A New York City condominium owner illegally converted his one-unit apartment into a duplex with 11 cramped sub-units, some of which had ceilings just 4 1/2 feet high, forcing his tenants to crouch or walk on their knees, officials alleged.

Inspectors with the city's Buildings Department raided the apartment on Manhattan's Lower East Side Aug. 14 after they got a complaint about the cramped conditions, The New York Post reported. The Henry Street building was listed as having 27 apartments on five floors, according to city records.

Owner Xue Ping Ni reportedly carved up the 634-square-foot unit into 11 units with no windows and an illegal bathroom. He was cited with numerous violations totaling $144,000.