A fourth person has been arrested and charged in connection with a human trafficking investigating involving a teenage girl.

It is alleged that on Dec. 30, 2018, a 17-year-old girl met two men in the Yonge Street and Dundas Street East area.

The two men allegedly befriended the girl, gave her drugs and alcohol, and then took her to Hamilton, where they sexually assaulted her.

The girl was then allegedly sexually assaulted by a third man.

The men then allegedly introduced the girl to a woman and she was then forced into the sex trade.

Photos of the girl were taken at various stages of undress and were then posted online advertising her sexual services.

It’s alleged that the first man controlled all the communications with the customers via text messages or phone calls, and the girl was told which sexual services she was to provide.

The girl was then allegedly forced to provide sexual services to numerous clients that attended the address in Hamilton, as well as provide sexual services to the first man as well. She was also allegedly forced to turn over all the money to him.

It’s further alleged that over the course of four days, the girl was forced to ingest a quantity of drugs, deprived of food and sleep, and was physically assaulted.

The girl managed to escape on Jan. 3, 2019 and call police.

That same month, Toronto police arrested two suspects, Charlton Sealy, 35, who police identified as the “second man,” and Shabaka Reid, 26, of Hamilton who police identified as the “third man.” Both face multiple charges including sexual assault, making child pornography and trafficking a person under 18.

One month later, police arrested Deanna Passera, 27. She is also facing multiple charges, including publishing child pornography, exercising control and trafficking a person under 18.

On Monday, Sudbury police arrested a fourth person, who police believed to be the “first man.”

Troy Thornhill, 37, of Toronto, is facing multiple charges, including sexual assault, trafficking a person under 18, assault, possession of child pornography.

Police say they are concerned there may be more victims.