London, England (CNN) -- Three women and a man who admitted to trafficking in underage girls have been sentenced to prison terms of more than two years each, British authorities announced Tuesday.
The three women and one man pleaded guilty to the charges Monday in Harrow Crown Court, north of London. They were arrested about a year ago and accused of bringing girls to London to sell them for sex.
"This is a sad and harrowing case that involved the main defendants effectively selling the virginity of girls as young as 13 for as much as 150,000 pounds ($231,300)," said Detective Chief Superintendent Richard Martin, head of the Metropolitan Police Service's Human Exploitation and Organized Crime Command.
Fatima Hagnegat, Marokh Jamali and Rasoul Gholampour pleaded guilty to conspiracy to traffic persons within the United Kingdom for sexual exploitation. Hagnegat and Jamali also pleaded guilty to control of prostitution for gain, police said.
Jamali and Gholampour received sentences of two years and nine months in prison, while Hagnegat was sentenced to two and a half years, court officials announced.
A 43-year-old woman who also pleaded guillty to trafficking conspiracy received a two-and-a-half-year prison term. Her name was withheld under British laws aimed at protecting the identities of children.
The investigation began in September 2009 after a woman dropped off a handwritten note at the Jumeirah Carlton Hotel in London's upscale Knightsbridge neighborhood. The note was addressed to the owner of the hotel and mentioned a rented house with girls available, though it didn't say for what, police said.
"I have 12 girls ready from the age 14-20 years, who are living all over the U.K.," the note read.
Concerned staff at the hotel alerted police, who traced the phone number on the note and the woman's car to an address in Wigan, near Manchester in northern England. That was where Hagnegat, 24, lived with her 30-year-old husband Gholampour, police said.
An undercover officer then called the number on the note to ask about hiring girls for a client. He spoke to Hagnegat's aunt, Marohkh Jamali, 41, who said she could arrange a party for four to five people that night with girls from Iran, England and Eastern Europe, police said.
The aunt said the girls would be between the ages of 14 and 20, police said.
A week later, the officer met Jamali at the Lancaster London hotel, which agreed with police to be the venue for the undercover officer's meetings with the defendants.
Jamali told the officer she could provide girls between the ages of 14 and 20. She said some of the girls were virgins, and that a number of them were available for a full range of sexual acts, police said.
Over the next two weeks, Jamali e-mailed the officer 28 times with pictures of several girls 14 and older, saying they were available for sex.
The officer then contacted Jamali to arrange a meeting with the girls. Jamali said she would bring four or five of them, including two 13-year-olds, to London and that she wanted at least 50,000 pounds ($77,000) and as much as 150,000 pounds ($231,300) for each one, police said.
Jamali went to the hotel the next day with Hagnegat and six girls, two of whom were 14, one who was 17, and others who were 18 or older. Officers then arrested Jamali and Hagnegat and took the six girls to a victims center, police said.
The girls told investigators that they traveled from Wigan, England, to London on the understanding they would earn money by dancing for a group of rich men. It was only once they arrived in London that they were told they may be asked to have sex with the men.
Gholampour was arrested when police then searched Hagnegat's home, and the 43-year-old owner of the apartment where the girls stayed the night before the London meeting was also arrested, police said. She could not be named for legal reasons, they said.
"This case highlights the fact that trafficking is not just a crime that involves foreign nationals being brought in the U.K. It is something that happens within the U.K. as well," Martin said. "We hope that this result will encourage any other potential victims to come forward and speak with police who may have felt that they couldn't do so before."