Toronto police believe there may be as many as 10 other victims being enslaved into the local sex trade as part of a recently uncovered human trafficking ring.

"We believe that there may be further victims, whether they are being held or unable to contact the police, or are fearful of the ramifications if they do so," Det. Sgt. Mike Ervick said Tuesday at a press conference.

Ervick said the victims are being held against their will and are "very vulnerable" because they don't speak English.

"They are controlled, their documents are taken from them, they are isolated, they are exploited," he said.

Ervick said it's difficult to tell how many women are being exploited by the alleged pimps, but he guessed the number is between six and 10.

The trafficking ring was uncovered last week after a young woman walked into a police station and told officers she was forced into sexual slavery.

Police quickly made six arrests in the case. A short time later, a second woman approached police with similar allegations, and officers arrested a seventh person.

Police allege the women were brought to Canada from Eastern Europe with fake passports, under the pretext they'd be working as models.

Police say the women were then held against their will when they arrived and told they'd be working as escorts for the ringleaders of the operation.

Investigators believe the human trafficking ring has been operating for more than a year. Ervick said the victims came to Canada recently and were earning between $4,000 and $10,000 a week for their pimps.

Four people, including a husband and wife from Toronto, have so far been charged with offences including trafficking in persons, exploitation, procuring a person to become a prostitute, living off the avails of prostitution, forcible confinement and threatening bodily harm.

The accused appeared in bail court on Tuesday, but their hearings were adjourned for two weeks.

Ervick is urging any other victims to call police 416-808-5206 or Crime Stoppers anonymously at 1-800-222-TIPS (8477), or go online at www.222tips.com.

He said interpreters are available on a 24-hour basis and police will "advocate on their behalf in regards to immigration."

The Toronto Sex Crimes Unit estimates between 600 and 800 people are brought to Canada illegally and forced into prostitution every year.

With a report from CTV Toronto's Janice Golding