DAYTON, Ohio (AP) _ A report that a police officer tortured a drug suspect with a hot iron during questioning has prompted calls from the NAACP and other community groups Thursday for the police chief to resign.

The groups urged the U.S. Justice Department to investigate the incident, which is already being investigated by the police department's Internal Affairs Bureau.

The Dayton Daily News, citing police investigative records, reported Wednesday that officer John Gamble last January used the iron to scorch David Greer three or four times while another officer pinned Greer face-up to a mattress.

Gamble kept asking the 18-year-old a question until Greer told him what he wanted to know after Gamble threatened to burn his genitals, the newspaper said.

Greer later pleaded guilty to aggravated drug trafficking, and was sentenced to three to 15 years in prison.

Both Greer and Gamble are black.

Gamble denied burning Greer until two other officers acknowledged June 7 that it had taken place, the Daily News said. Gamble made a tape-recorded statement to police July 6.

''I did it,'' the newspaper quoted Gamble as saying. ''I'm not proud of it. It happened. There's nothing I can do about it now. I wish it didn't, but it did, and it's time for me to deal with it.''

Montgomery County Prosecutor Lee Falke announced he had appointed a special prosecutor to determine whether criminal charges were warranted.

The Daily News story triggered calls Thursday for the resignation of Police Chief James Newby by local chapters of the National Association for the Advancement of Colored People, the Southern Christian Leadership Conference and the Urban League, as well as the Interdenominational Ministerial Alliance.

''We are outraged and disappointed, but not surprised at this latest incident of police brutality and the subsequent attempt to cover up this brutal act,'' said NAACP chapter President Jessie Gooding. ''This highlights the pattern of ongoing police brutality and injustice in the Dayton Police Department.''

The Rev. William T. Head, an investigator for the NAACP, said Newby is responsible for his officers' actions.

''Finally, the community has knowledge that the police are not above lying and are not above committing illegal acts,'' said Head. ''It's time for Chief Newby to step aside.''

Head, who has led efforts to investigate other alleged instances of police brutality, said the officer's race was irrelevant.

''He's a policeman,'' Head said. ''He's wrong.''

Newby declined to comment on the call for his resignation.

''There was no coverup,'' he said, pointing out that the investigation was initiated by the police department and that the information reported by the newspaper was uncovered by police investigators.

Newby said that when he first learned of the allegations, his reaction was ''somewhere between (being) sick to my stomach (and) disgust.'' He said he expects to announce some disciplinary action Friday.

County Prosecutor Falke said prosecutors first became aware of the allegations against Gamble last March, but were skeptical and decided to wait until the police department completed its investigation.

''My assistant just couldn't believe it,'' Falke said.