The mosque developers are tax deadbeats. Sharif El-Gamal, the leading organizer behind the mosque and community center near Ground Zero, owes $224,270.77 in back property tax on the site, city records show. El-Gamal's company, 45 Park Place Partners, failed to pay its half-yearly bills in January and July, according to the city Finance Department. The delinquency is a possible violation of El-Gamal's lease with Con Edison, which owns half of the proposed building site on Park Place. El-Gamal owns the other half but must pay taxes on the entire parcel.