Alpharetta has responded to an appeal by the Islamic Center of North Fulton that seeks to overturn a District Court ruling that upheld the city's right to deny the mosque's expansion plans.

In papers filed Thursday with the U.S. 11th Circuit Court of Appeals, the city says U.S. District Judge J. Owen Forrester was correct in January when he dismissed claims by the center that the city infringed on its ability to exercise religion by denying the expansion. He ruled the city's action created no such burden on the center, at least no burden it could not have anticipated when it bought the property in 1998.

The case has drawn the interest of the U.S. Justice Department, which is continuing its own investigation under a federal law that requires local governments to prove decisions made in zoning cases are not discriminatory and serve public need.

The Alpharetta City Council voted 6-0 in May 2010 to reject plans by the center to tear down its 2,500-square-foot worship house and construct two buildings: a 1,900-square-foot multipurpose facility and a 12,000-square-foot, two-story structure to serve as its main building. Council members said they were concerned that the worship center was backing out of previous agreements not to expand, made before Alpharetta annexed the property from Fulton County in 2005.

"We pointed out that none of those burdens that they alleged rise to the level of 'substantial' as referred to in the act," City Attorney Sam Thomas said. "The [zoning laws] existed when they came there, and they've continued to exercise their religious rights."