A woman is assisting police after a baby boy was found dead inside a stormwater drain.

The confronting discovery was made by two workers carrying out routine maintenance in Alexander Heights in Perth’s northern suburbs on Monday afternoon.

Western Australia Police confirmed a woman in her 30s is assisting with their investigation into the newborn’s death.

“The woman is receiving appropriate care and support,” police said on Wednesday night.

“Given the sensitivities, we will be making no further comment at this time.

“The Western Australia Police Force would like to thank the community for their concern, support and assistance.”

Police had earlier confirmed the infant was put in the stormwater drain in recent days.

There was no evidence the baby had been washed through the drain system, Detective Senior Sergeant Stephen Cleal said on Tuesday.

Detectives had made a plea for the baby’s mother to come forward amid concerns for her health.

Police also urged people with information about the incident or CCTV recorded in the area to come forward.

WA Premier Roger Cook had called it a “horrifying series of events” that had rocked the community.

“This goes to the heart of everyone’s sense of humanity, a small child whose life has passed under tragic circumstances,” he said.

Flowers and teddy bears were left at the drain site this week.

-AAP