Starbucks London 2012 2
A man carrying an umbrella walks in the rain past a Starbucks coffee shop in London. Reuters

How many Frappuccinos can you buy with $30,000? Sounds like the U.S. Department of Homeland Security (DHS) might be able to help you with that answer, as its employees spent that much at Starbucks last year alone, according to a new investigation by NBC-4 Washington's Scott MacFarlane.

The coffee chain made a total of thirty grand from "micropurchases" by a number of DHS employees who are given "purchase cards" on which they can spend as much as $3,000 without publicly disclosing the expenditures, according to documents obtained by the news network via Freedom Of Information Act (FOIA) requests.

The coffee slurping going on at Homeland Security is just one portion of a large federal outlay. American taxpayers are footing the bill for at least $20 billion in federal employee micropurchases so far this year -- that's 2,000 million bucks we're shelling out to "support" a program shrouded in secrecy.

The House Oversight subcommittee took up the rising controversy over micropurchases on the federal dole earlier this month during a hearing in which they inquired about why government employees at a wide range of agencies used their purchase cards on haircuts, gym feees and movie tickets, the Washington Post reported.

After being presented with the results of the network's investigation, Rep. John Mica, R-Fla., chair of the subcommittee, told NBC-4 Washington: “When you have $10,000 being spent at one Starbucks by DHS employees in one city in six months, someone is abusing the purchasing permission that we've given them."

But DHS spokesman Sy Lee told the Washington Post a different version of events: “[The micropurchases] were made for various reasons, following standard purchase card policy and guidance.”

Federal agency auditor Anne Richards wrote in testimony submitted to the House subcommittee that 9,700 DHS employees have purchase cards, which are supposed to make inexpensive purchases easier to handle.

“Every transaction has inherent risk — the risk of purchase card misuse is greater because of the number of cardholders and the low dollar, decentralized actions, which are subject to fewer reviews and controls,” she said, according to NBC 4-Washington. “However, this increased risk was purposely chosen to reap the benefits — less cost and quicker response — of the simplified procurement process.”