A .50-caliber rifle capable of shooting down a helicopter was found inside the hideout of drug boss Joaquin "El Chapo" Guzman, which the Bureau of Alcohol, Tobacco and Firearms says was sold and lost through the U.S. government's botched gun-smuggling operation known as Fast and Furious.

Officials confiscated a number of weapons after the Sinaloa Cartel kingpin was recaptured earlier this month in a raid on a house in the Mexican city of Los Mochis. ATF agents checked the serial numbers and determined that the .50-caliber came from the agency's Fast and Furious program, according to Fox News.

Between 2006 and 2011, ATF agents in the Tuscon and Phoenix area intentionally allowed licensed firearms dealers to sell guns illegally to men they thought were connected to Mexican drug cartels, intending to track the guns to cartel leaders and arrest them. However, the ATF lost track of 1,400 of the 2,000 weapons.

Numerous guns were linked to crimes, including two purchased by Guzman's Sinaloa Cartel that were connected to the 2010 shooting death of U.S. Border Patrol agent Brian Terry, according to The Daily Mail.

In all, 34 of the 2,000 weapons sold under Fast and Furious were .50-caliber rifles like the one found in Guzman's house. The crime boss reportedly placed guards on hilltops with orders to shoot down helicopters if they approached looking for him.

Federal officials are still investigating how many weapons found at Guzman's hideout came from the U.S., and where they were purchased, according to Fox News.

The Fast and Furious program became a major point of contention between congressional Republicans and the Obama administration during the president's first term.

Former Attorney General Eric Holder was held in contempt of Congress for refusing to hand over records about the operation to investigators.

President Obama then attempted to use executive privilege to prevent Congress from obtaining the records, but a federal judge ruled on Tuesday that Obama does not have such authority and ordered the administration to release the documents, reported The Hill.