Pc Jason Hanvey held the woman in a "cruel position", the court heard
Two policemen have been jailed for 18 months after inflicting "deliberate cruelty" on a 19-year-old woman in custody in Manchester.
Pc Jason Hanvey, 37, and Sgt Andrew Kennedy, 51, showed "appalling and inexcusable conduct" at Collyhurst police station in 2008, a jury heard.
Judge Anthony Gee QC said: "It was little short of torture."
They were convicted of misconduct in a public office after a trial at Manchester Crown Court.
Judge Gee said: "You have brought disgrace upon yourself and the uniform that each of you have been privileged to wear," he said.
"Each of you abused your position in a shameful and deliberate fashion towards a 19-year-old girl."
Hanvey, of Dukinfield, hit a male suspect in the face in similar circumstances at another police station 12 years ago, the court heard.
He was convicted of assault by magistrates in Manchester, but was allowed to keep his job because of previous good character.
In October 2008 Hanvey was filmed by CCTV cameras holding the woman's face on a desk, while threatening her, the court heard.
He screamed at Amy Keigher and threatened to "rip her skull off".
The judge said he also grabbed her hair, put her hands in handcuffs and pulled them over her head for more than a minute in a "cruel position".
Sgt Andrew Kennedy failed to intervene, the court was told
The Greater Manchester Police officer then told her to say "pretty please" to be released.
"You were a bullying thug on this occasion. This was deliberate cruelty and quite appalling and inexcusable conduct," the judge told him.
Kennedy, a senior desk officer from Atherton, stood by his side and showed "complete indifference" as he failed to intervene, the court heard.
Judge Gee told Kennedy that although Hanvey was the principal offender, he regarded his culpability and blameworthiness as "just as high".
"You could, and should, have stopped what was happening," he said.
Miss Keigher had been arrested in Piccadilly Gardens in Manchester city centre on suspicion of assault and was later charged.
The incident came to light when she complained about her treatment and the CCTV tape was reviewed.
The Independent Police Complaints Commission (IPCC) led an investigation into the incident.
Kennedy had no previous convictions but was subject to disciplinary hearings in 1999 and 2000 for neglect of duty.
Hanvey has now resigned and Kennedy has retired.
Timothy Storrie, defending both men, said Hanvey had forfeited nearly £900,000 in future earnings and pension benefits, while Kennedy, with 27 years of service, would lose up to £300,000.
Ch Supt Dave Keller, of GMP's Professional Standards Branch, said in a statement: "The conduct of Hanvey and Kennedy that day fell well below the standard expected of professional police officers and I am happy that justice has now been served.
"However, I want to stress their actions in no way reflect the committed and professional attitude shown by the vast majority of our custody staff."
The police refused to release the CCTV footage of the incident to the media, "to ensure future disciplinary hearings are not compromised".
Judge Gee said to the pair: "During the time we have had together I have detected in neither of you not one hint of remorse or regret for what happened that night.
"In the witness box you sought to justify what you did in what I regard as an arrogant fashion."