HOUSTON — Tenants of the Harris County Housing Authority got $8,500 in gift cards to Walmart for Christmas in 2011, courtesy of federal taxpayers.

But that sort of unrestrained spending — on tenants, on memorabilia, on failed real estate deals, on its own salaries and especially on contracts with two firms connected to two former board members — has dissipated the agency’s fund balances from $37.9 million to $1.6 million between 2009 and 2012, according to an audit recently published by the inspector general of the Texas Department of Housing and Urban Development.