An Ottawa elementary school teacher is among 57 people who were arrested in a nation-wide investigation into Internet-based child sexual abuse.

Grade 5 teacher Paul Andre Dumais, 33, who works at Jeanne Sauve Elementary School in Orleans, was charged with one count of possessing child pornography earlier this week.

Dumais is one of seven men and one woman in the Ottawa-Gatineau area who face various child sexual abuse charges, including possession of child pornography and possession of a substance for the purpose of trafficking.

An arrest warrant has also been issued for Michael Kennefick, 22, of Ottawa, who is currently outside the country.

The arrests are part of "Project Salvo," the largest-ever co-ordinated investigation of Internet-based child sexual abuse in Canada.

Police say more search warrants are expected to be executed across the country in the coming weeks.