Nigerian Nnanyere David Nwankwo, 24, told friends he was kicked and attacked by officers during a raid at his Tottenham home.
A second man, Ajah Mpakaboari, 33, was left bleeding after he was also allegedly assaulted during a search by Enfield police officers in November last year.
Six police officers faced being interviewed as criminal suspects over claims they tortured the suspected criminals, falsified evidence and stole property.
A third Nigerian connected to the address, Bernasko Adji, 36, was charged with assaulting a constable during the Brantwood Road raid.
But the charge, and a drug smuggling case against the trio, and a man and a woman held at a separate address, was dropped by prosecutors three months ago.
They said proceeding with it could prejudice the wide-ranging inquiry into suspected criminal activities by a number of officers.
A second team of officers arrested Victoria Seabrook, 24, and Nicholas Oforka, 25, at another property in Hertford Road, Enfield.
Speaking through her solicitor, Ms Seabrook said her friends were injured during the nearby raid in which police claimed two sacks of cannabis were found.
Solicitor Shenel Johnson, of SJ Law in Walthamstow, said: "Nnanyere Nwankwo, who she knew as David, told her that, after the arrest, the police were kicking him and put his head down a toilet and repeatedly flushed it.
"He also had a cut on his hand when he got to custody. She also heard that Ajah Mpakaboari had blood on his clothing when he got to the police station."
Ms Johnson said her client, who was pregnant at the time of her arrest, was forced to get dressed in front of three male police officers and was not allowed to use the toilet.
She said a pair of sunglasses and an electric hand-held fan also went missing during the police operation.
Officials at the Independent Police Complaints Commission (IPCC) have launched an inquiry into a series of allegations.
The most serious was a claim some of the men were effectively "waterboarded" during questioning at the Tottenham property.
The simulated drowning technique became notorious after its use by United States CIA interrogators on Guantanamo Bay terror suspects.
It involves pouring water on to cloth or plastic held over the victim's face, causing them to feel as if they are suffocating.
The claims emerged during an anti-corruption inquiry into officers based at Edmonton police station in Enfield, north London.
All of the officers, who include a detective sergeant, could face prosecution if there is enough evidence against them, and ultimately the sack.
Commissioner Sir Paul Stephenson has appointed a new borough commander in Enfield as the claims provoked outrage.
Suspicions arose over the behaviour of the officers shortly after the raids at homes in Enfield and Tottenham on November 4 last year.
It is understood a Metropolitan Police officer later came forward to internal investigators with information against several colleagues.
An inquiry was launched by members of the Directorate of Professional Standards (DPS) into allegations that the suspects' property was mishandled.
In February, Scotland Yard said nine officers from the Enfield crime squad have been suspended and two placed on restricted duties, effectively shutting it down.
But the scope of the probe widened when shocking new information alleging that the suspects were tortured came to light.
Because of the seriousness of the case, files were passed to IPCC officials on April 3.
The police watchdog then launched its own inquiry into the actions of the six officers, who have all been suspended.
Officials undertook further house-to-house inquiries, appealed for witnesses and took statements from officers.
Meanwhile the case against the drug suspects was quietly dropped at Wood Green Crown Court on 18 March.
In a secret session, a Crown Prosecution Service (CPS) solicitor told a judge that it would not be in the public interest to proceed.
A spokeswoman said: "The Crown Prosecution Service took the decision to offer no evidence in this case at trial as it would not be in the public interest to proceed.
"To do so would have compromised a wide-ranging criminal investigation into a number of police officers."
London Mayor Boris Johnson, who chairs the Metropolitan Police Authority (MPA), said: "Clearly these allegations are extremely serious and need to be thoroughly investigated."
Liberal Democrat home affairs spokesman Chris Huhne said the allegations were "appalling and shocking".
MPA member Reshard Auladin, who works as a magistrate in Enfield, said the claims were being "thoroughly investigated".
Fellow MPA member Jenny Jones added that the claims were "unbelievable" and "absolutely shocking".
She said she was surprised at how long it has taken for the allegations to surface and said it may be because the individuals did not think they would be taken seriously.
Ms Jones said: "If these accusations are substantiated then serious disciplinary action must be taken against those involved, and a thorough investigation into how it could have happened.
"The police should be a public protector, ensuring community safety, not an organisation that uses criminal torture tactics."
An MPA spokesman said any behaviour that "impacts negatively on community confidence" will not be tolerated.
Enfield borough commander Chief Superintendent Adrian Hanstock has been moved to New Scotland Yard to take on organisational strategy and policy.
In March, Mr Hanstock told a local newspaper that the corruption inquiry, at that time focusing on property claims, was part of holding police to account.
He said: "We're not talking about Life On Mars-style corruption. This is about procedural compliance."
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