Suspicious letter closes Sydney police HQ

Parts of the NSW Police headquarters have been locked down after staff received a letter containing suspicious residue.

Hazmat teams were called to the building on Charles Street, Parramatta, just after 11am on Wednesday and are currently examining the letter, police say.

Paramedics were also called to the scene but no one required treatment.

The office within the building where the letter was opened has been isolated as a precaution..