Montgomery County planning officials are investigating possible wrongdoing in the 1999 approval of a housing development that resulted in a century-old private gravel access road, used by a Sandy Spring community of predominantly elderly African Americans, being dropped from state tax maps.

The exclusion of what residents call “Farm Road” has been the subject of multiple lawsuits and bitter debate between the county planning department and the community, which was founded by freed slaves. The road’s absence from tax maps effectively leaves about a dozen owners with land that has little or no market value. Without proof of a road for ambulance or firetruck access, the county will not assign addresses, which are required for building permits.

Many of the residents along the road have been lobbying county officials for years to reinstate the road, but until recently have not had any success.

“It’s gone on too long,” said Sheldon Carter, 45, whose wife’s family owns two acres along the disputed road. “I need a place to build, and we can’t build. . . . What am I supposed to tell my kids when they ask, ‘Daddy, why can’t we get our house built?’ ”

Francoise Carrier, chairman of the Montgomery County Planning Board, said Monday evening that she will appoint an independent third party to investigate the 1999 application by Winchester Homes to build Dellabrooke, a subdivision of 43 high-end single-family homes on a 111-acre site on Goldmine Road between New Hampshire Avenue and Olney-Sandy Spring Road.

Several of the new homes were built on Farm Road, blocking access from Goldmine. In 2006, a homeowner put up a chain at the other end of the road, blocking access from Brooke Road. For years, the planning agency said that it regarded the situation as a dispute among neighbors and that the road was just a pathway.

Carrier said she is initiating the review because of allegations made in a 2007 affidavit, which recently resurfaced, from Adrienne Gude Lewis, a former aide to County Council member Marc Elrich (D-At Large). She charged that the engineering firm working for Winchester — Macris, Hendricks & Glascock — “submitted a series of false and misleading plans” to the planning board that failed to note the existence of Farm Road. Moreover, Gude Lewis alleged that “an environment and system exists” within the county planning bureaucracy “that invites and, in some cases, facilitates deliberate abuse by those inclined to exploit its flaws.”

The affidavit, part of a lawsuit since dismissed, does not elaborate. Its existence was first reported by WUSA (Channel 9).

Michael Lemon, Winchester’s development manager, did not respond to a phone message Tuesday. Jim Hendricks of Macris, Hendricks & Glascock declined to comment and directed a call to his attorney, Jim Lee. Lee did not respond to a phone message Tuesday.

Carrier also said she would write a letter to the Maryland Department of Planning asking that it consider amending its tax maps to include the road. In 2007, the state planning department, based on new surveying information, was preparing to restore Farm Road to the tax maps. But state officials backed off after an intervention by Adrian Gardner, attorney for the Maryland-National Capital Park and Planning Commission, who cited concerns about ongoing litigation over the properties.

Elrich, who has urged Carrier to act, said state action would be the simplest way to put a halt to what he called “an embarrassing charade” by the planning agency that the road does not exist.

“Park and Planning became more focused on defending their decision than doing what was right,” he said. “They became more focused on protecting the agency rather than the public.”

Carrier announced the investigation Monday during an emotional meeting with property owners at the Sandy Spring Slave Museum.

“I understand what this land means to you,” Carrier said. “We want you to be able to make the best use of it possible. That is a shared goal.”

Property owners said they were pleased with Carrier’s announcement but expressed bitterness at the longtime official indifference to their situation.

William Rounds, 72, who has been refused an address for a property where he once had two houses, said he welcomed Carrier’s announcement but added, “I would have to see something on paper to believe anything Park and Planning says.”