A 49-year-old woman accused of having sex with a minor will be forced to have her pelvic region photographed, after a magistrate ruled the images could help prove or disprove sexual assault charges against her.

Katrina Arredondo​ was a youth officer at the Melbourne Juvenile Justice Centre in Parkville in the 1990s, when she allegedly had sex with a boy detained at the centre, and after his release, between 1994 and 1995.

Credit:Penny Stephens

The boy was 15 at the time of the first alleged offence. She was 27.

Detective senior constable Sarah Kendall told Melbourne Magistrate's Court on Friday the boy told a Department of Human Services worker about the alleged abuse in 1996.