Police have today conducted simultaneous raids across Sydney's south-west, smashing what they allege is a child prostitution ring involving children as young as 13.

This website understands a 22-year-old Warwick Farm woman, previously charged with promoting child prostitution, obtaining benefit from child prostitution and armed robbery, has been rearrested, along with three others.

Strike Force Woodvale, comprising detectives from Liverpool Local Area Command, was established in February this year to investigate alleged child prostitution in the Warwick Farm area.

Detectives have this morning arrested four people allegedly involved in the prostitution, and have not ruled out further arrests.

Police will address the media following the laying of charges.

When the 22-year-old woman was first arrested in March, police spoke of their fears that she had arranged for girls as young as 13 to participate in acts of prostitution.

Lisa Davies is the Herald's Crime Editor