A federal immigration officer who was recorded demanding sex from a woman in exchange for a green card has pleaded guilty.

Isaac Baichu pleaded guilty to all the charges against him Wednesday in Queens. The 48-year-old is expected to receive a prison sentence of 1 1/2 to 4 1/2 years.

The case involved a Colombian woman married to an American citizen. The woman said she gave in to one sex demand in December 2007 because she was afraid, but she used a mobile phone hidden in her purse to record the encounter.

She took the recording to The New York Times and to the Queens district attorney's office.

Baichu was arrested in March 2008 after meeting with the woman again, this time with prosecutors listening in.