The D.C. Housing Authority said Monday that it was reviewing privacy policies and retraining staff after The Washington Post disclosed that Mayor Vincent C. Gray’s 2010 campaign had used a list of public housing residents.

Adrianne Todman, the authority’s executive director, said in a statement that the list’s use was “unauthorized” and that she was “very concerned” about the apparent breach of laws and policies protecting residents’ privacy.

“We take our role in safeguarding the privacy of our clients seriously,” Todman said. “If it is discovered that staff action led to an unlawful release of such a list, strong disciplinary action will be taken and we will refer the matter to the appropriate authorities.”

It is not clear how the Gray campaign obtained the list, which contained residents’ names, addresses and phone numbers. Several Gray campaign volunteers were also Housing Authority employees, including the mayor’s son, Carlos Gray, who denied knowing about the database.

Campaign workers said they used the list, of nearly 6,000 residents living in about 40 DCHA properties, to identify potential voters and get them to the polls during the closely fought Democratic primary race against incumbent Adrian M. Fenty. Big margins racked up in public-housing-heavy precincts helped propel Gray to a 13,000-vote win.

The authority previously said it did not release the information and would not have done so even under a public records request.

Although lists of voter names and other information are frequently used by campaigns, the precision and thoroughness of the database used by the Gray campaign would be difficult to replicate through legitimate means. A list of residents — as opposed to a list of registered voters, which is public — was particularly valuable in the 2010 primary, the first time the city allowed same-day registration for voters.

Todman said the authority contacted its residents Monday to assure them that “privacy is of utmost concern.”

Dena Michaelson, a spokeswoman for the authority, said an “internal review” of privacy-related procedures is underway. “We’re also reinforcing the privacy requirements with all of our staff,” she added.

Gray told The Post earlier that he was not aware the campaign had a list of public housing residents and that he doubted whether such a list would have been effective. A spokesman for Gray had no additional comment Monday.

The existence of the database and the campaign’s alleged use is the latest in a series of revelations about Gray’s 2010 election, which U.S. Attorney Ronald C. Machen Jr. has said was “compromised by backroom deals, secret payments and a flood of unreported cash.”

Machen’s inquiry has led to guilty pleas from two campaign aides in a scheme to secretly pay a minor mayoral candidate to disparage Fenty and, more recently, a public relations consultant who admitted to orchestrating a $653,800 off-the-books “shadow campaign” to help elect Gray.