Washington (CNN) -- Mexican drug cartels have used cash and sexual favors as tools to corrupt U.S. border and customs agents, an inspector general investigation has found.

In exchange, agents allow contraband or unauthorized immigrants through inspection lanes, protect or escort traffickers or leak sensitive information, said Charles Edwards, acting inspector general of the Department of Homeland Security.

Testifying before a Senate subcommittee, Edwards cited the Zetas drug cartel as one of the leaders "involved increasingly in systematic corruption."

He did not elaborate on how non-cash methods of corruption, like sexual favors, have been used to corrupt agents.

Since October 2004, 127 Customs and Border Protection employees have been arrested or indicted for acts of corruption, said agency Commissioner Alan Bersin, speaking at the same hearing of the Senate Subcommittee on Disaster Recovery and Intergovernmental Affairs.

Mexican President Felipe Calderon's offensive against the drug cartels, combined with a surge in the hiring of border agents in recent years, have multiplied the risks of corruption, Bersin said.

Today, the Border Patrol counts more than 20,700 agents, more than double its size in 2004. Bersin implied that the rapid hiring spree may have come at the cost of hiring less qualified agents.

"The accelerated hiring pace under which we operated between 2006 and 2008 -- and, frankly, mistakes from which we are learning -- exposed critical organizational and individual vulnerabilities within CBP," he said.

To face this challenge, the commissioner touted the passage of the Anti-Border Corruption Act of 2010, which requires that by 2013, all the agency's law enforcement applicants must receive a polygraph test before being hired. It also calls for periodic reinvestigations into the background of its agents.

Now, provide a numbered list of answers to these questions:

1. who is the president of Mexico?
2. How many are working for border patrol today?
3. Is this the same as in 2004?
4. How many employees have been arrested?
5. Between what years was the higher hiring rate?
6. who is the acting inspector general mentioned?
7. what organization does he work for?
8. Is cash used for corruption?
9. what about non-cash?
10. what is the non-cash example used?
11. what drug cartel is mentioned?
12. who is being corrupted?
13. what tests are the agents supposed to receive?
14. by when?
15. according to what act?
16. who is the commissioner mentioned?
17. where was he speaking?
18. Do agents leak private information?
19. What else do they do?
20. What did Edwards call the corruption?

Numbered answers:
1. Felipe Calderon
2. more than 20,700 agents,
3. no
4. 127
5. between 2006 and 2008
6. Charles Edwards,
7. Department of Homeland Security.
8. yes
9. yes
10. sexual favors
11. Zetas drug cartel
12. U.S. border and customs agents,
13. a polygraph test
14. by 2013
15. he Anti-Border Corruption Act of 2010,
16. Alan Bersin
17. a hearing of the Senate Subcommittee on Disaster Recovery and Intergovernmental Affairs.
18. yes
19. allow contraband or unauthorized immigrants through inspection lanes,
20. systematic corruption.