Boca Raton officials were biased and trampled on a developer's due-process rights when they denied a permit to build a sprawling duplex on oceanfront land, a new lawsuit claims.

Azure Development LLC, a Delray Beach-based luxury home developer, asked permission to build a 14,270-square-foot, four-story duplex on a vacant half-acre parcel it owns at 2600 N. Ocean Blvd. Construction would require a city variance as exception to development regulations in that area.

The property is east of the coastal construction control line, a state-designated boundary intended to mitigate impacts on sand, dunes and turtles. In Boca Raton, construction east of the line is allowed only with a variance and after a development company shows its project won't be environmentally harmful.