(CNN) -- Two employees at the Baltimore, Maryland, branch of the liberal community organizing group ACORN were caught on tape allegedly offering advice to a pair posing as a pimp and prostitute on setting up a prostitution ring and evading the IRS.

The footage, which appears to have been edited in places, was recorded and posted online Thursday.

The video footage -- which has been edited and goes to black in some areas -- was recorded and posted online Thursday by James O'Keefe, a conservative activist. He was joined on the video by another conservative, Hannah Giles, who posed as the prostitute in the filmmakers' undercover sting.

The video shows the pair approaching two women working at the ACORN Baltimore office and asking them for advice on how to set up a prostitution ring involving more than a dozen underage girls from El Salvador.

One of the ACORN workers suggests that Giles refer to herself as a "performing artist" on tax forms and declare some of the girls as dependents to receive child tax credits.

"Stop saying prostitution," the woman, identified by the filmmaker as an ACORN tax expert, tells Giles. The other woman tells them, "You want to keep them clean ... make sure they go to school." Watch tape of alleged advice on prostitution »

Both women appear enthusiastic to help.

Calls to ACORN's Baltimore offices were not immediately returned Thursday.

Stuart Katzenberg, lead organizer for ACORN's Maryland chapter, told the Baltimore Sun that both ACORN employees were fired because they "did not meet ACORN's standards of professionalism."

Sonja Merchant-Jones, chair of Baltimore City ACORN, told CNN affiliate WMAR-TV that the fired workers were seasonal, part-time employees and that no senior ACORN staff members were in the building at the time the film was made.

Scott Levenson, a spokesman at ACORN's national offices said, "The portrayal is false and defamatory and an attempt at 'gotcha journalism.'

"This film crew tried to pull this sham at other offices and failed. ACORN wants to see the full video before commenting further," Levenson said.

The conservative filmmakers unsuccessfully attempted similar ruses at the group's offices in Philadelphia, Pennsylvania, Los Angeles, California, and New York, Levenson said.

Law enforcement officials in the Baltimore area wouldn't confirm whether they are investigating the alleged incident at the local ACORN office. However, authorities said that under Maryland law, such undercover video may not be admissible in court as evidence.

CNN attempted to reach O'Keefe and Giles; O'Keefe was not available for comment and Giles canceled an interview scheduled for Thursday.

ACORN -- an acronym for the Association of Community Organizations for Reform Now -- made headlines last year when Republican groups seized on allegations of voter registration fraud by the group in Florida and several other states, claiming its workers were trying to push the election in Barack Obama's favor.

On Wednesday, arrest warrants were issued for 11 Florida voter registration workers suspected of submitting false information on hundreds of voter registration cards, according to court documents. The Florida investigation was triggered by ACORN officials who noticed irregularities in forms they were receiving.

Founded in 1970, ACORN calls itself "the nation's largest grassroots community organization of low- and moderate-income people." The group says it has more than 400,000 member families organized into more than 1,200 neighborhood chapters in 110 cities.

Besides voter registration, the group focuses on issues such as predatory lending, the minimum wage and funding for public schools, according to its Web site. It also provides free tax-return preparation for low-income people and screening for state and federal benefit programs.

CNN's Bill Tucker, Chris Murphey and Steve Turnham contributed to this report.

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