(Writes through with news conference, congressional investigations) By Maggie Fox, Health and Science Editor WASHINGTON, May 31 (Reuters) - The U.S. Homeland Security Department said on Thursday it was investigating how a newlywed lawyer with a dangerous form of tuberculosis slipped through borders despite orders to detain him. The patient, 31-year-old Andrew Speaker of Atlanta, arrived at a specialist hospital in Denver for treatment for his infection, known as extensively drug-resistant tuberculosis or XDR TB. "There is an investigation into what transpired at the port of entry," Homeland Security Department spokesman Russ Knocke said in a telephone interview. He said all officers at all ports of entry into the United States had Speaker's name and were told to detain him and contact the local public health department. "The system worked," Knocke said. "The information was actually sent out to all ports everywhere for all port officers to access on the 22nd of May." But Speaker slid through on the 24th of May, driving from Montreal to New York. An officer may have mistakenly waved him through, Knocke said. Speaker could also have fooled someone. "Let's not forget that he was pretty deceitful," Knocke said. Members of Congress said they would investigate how border agents and the U.S. Centers for Disease Control and Prevention handled the case. "This incident only reinforces my concern about our nation's ability to cope with a major outbreak, whether naturally occurring, as in this case, or intentional," said Sen. Susan Collins, ranking Republican on the Senate Homeland Security and Governmental Affairs Committee. FATHER-IN-LAW SURPRISE Speaker's father-in-law, Robert Cooksey, revealed he has worked at the CDC for 32 years in the Division of Tuberculosis. The twist in the story of a newlywed couple who hopscotched across Europe to Canada ahead of health authorities trying to stop them raised immediate questions about how Speaker became infected. "I do not have TB, nor have I ever had TB," Cooksey said in a statement. "My son-in-law's TB did not originate from myself or the CDC's labs, which operate under the highest levels of biosecurity." Speaker was the first patient to be isolated under a federal order in 44 years. His flight forced the CDC, the World Health Organization and European authorities to track down about 100 people who may have been in close contact with him on trans-Atlantic flights. Speaker was scheduled to undergo treatment that would include oral and intravenous antibiotics and perhaps surgery. Dr. Gwen Huitt, an infectious diseases expert at National Jewish Medical and Research Center in Denver who is treating Speaker, said he was diagnosed with tuberculosis by accident, after being X-rayed for a rib injury. "He has a fairly extensive travel history over the past six years," Huitt told a news conference. "We don't have any idea where he contracted it." He may need surgery to remove infected tissue and can expect to be on a cocktail of antibiotics for two years, she said. She estimated the total cost at $250,000 to $350,000. Speaker's insurance company said it paid $12,000 to fly him from Atlanta to Denver. (Additional reporting by Will Dunham in Washington)