A 17-year veteran of the Greater Sudbury Police Service pleaded not guilty to charges of discreditable conduct at a disciplinary hearing Tuesday morning.

Constable Robert Rheaume is accused of discrediting the service in March of 2018 after posting several comments on Facebook criticizing the salaries of four civilian staff members, all women.

Those posts were widely-circulated within the ranks of the service.

The officer defended his posts, citing free speech, but an internal investigation found Rheaume had breached the police service's social media and workplace harassment policies.

In his defence, Rheaume says neither the internal policies nor the Police Services Act supersede the Charter of Rights and Freedoms.

The prosecutor told the hearing committee on Tuesday that Rheaume's free speech argument should not apply because he says as a police officer, he is a public figure, required to balance his charter rights with the expectation of loyalty to his employer.

The hearing is expected to last two days.

CTV Northern Ontario's Callam Rodya wil have more on this story later today.