Police in Hamilton, Ont., say nine people have been arrested in a six-month multi-jurisdictional investigation, called Project Links, which was triggered by a seven-year-old girl who said she was being sexually abused by her mother’s boyfriend.

A 34-year-old Hamilton man is facing 40 charges. The majority of the charges include sexual assault, sexual interference, and making, possessing and distributing child pornography.

Hamilton police said they received a tip from the Hamilton Catholic Children’s Aid Society on May 3, 2016, that a seven-year-old girl told investigators she was being sexually abused. The main suspect was arrested later that day.

Police searched a Hamilton residence the next day and seized numerous electronic devices and property. During the investigation, detectives discovered another minor related to the victim was also a victim of sexual assault. Police said the seven-year-old girl was sexually assaulted by more than one person and that she was “being made available” in ads posted on the U.S. classified website Craigslist.

Eight other suspects have been arrested in connection with the case, according to Det. Sgt. David Dunbar from Hamilton Police’s Victims of Crime branch. Dunbar said that detectives from Project Links executed 14 search warrants and 15 production orders, and seized more than 100 electronic devices and computers.

“We believe these arrests have prevented other children from being sexually abused or being exposed to imminent dangers,” Dunbar said.

The investigation led to eight other arrests. The other suspects arrested include a 36-year-old man from Hamilton, a 50-year-old man from Hamilton, a 38-year-old man from Waterloo, Ont., and a 48-year-old woman from Waterloo, Ont., a 52-year-old man from St. Catharines, Ont. and a 35-year-old man from Waterloo, Ont. Another 39-year-old woman from Hamilton was arrested and charged with failing to provide the necessities of life to a child and has been released on a promise to appear in court.

The names of others arrested are under a publication ban to protect the identities of the victims.

Police identified another man, 48-year-old Geoffrey Burnet of Kitchener, Ont., who was arrested and charged with making and distributing child pornography. Police said Burnet is a former elementary school teacher in several boards in southern Ontario. He is also facing more charges related to a historical sexual assault case.

According to a statement released by Columbia International College, a Hamilton private school, Burnet worked at the school on contract starting in 2014. His employment was terminated in September.

Police say none of the charges against Burnet are related to any students at the private school, the school said in a statement.

Out of concern for the safety of other children in other jurisdictions, Hamilton police had shared information with other police agencies including the U.S. Department of Homeland Security, the Ontario Provincial Police, the Niagara Regional Police, the Waterloo Police Service and the Chatham-Kent Police Service.

Hamilton police said they believe there could be other victims and encouraged anyone with information related to the case to come forward.