Warning to families after dangerous fishing line discovery at Secret Harbour playground

A local mother is warning others to check playgrounds before letting their kids explore after making a dangerous discovery.

Aimee Jansen took her children to The Harbour Playground in Secret Harbour on Sunday when she spotted a piece of fishing line tied tightly between climbing ropes.

After removing the line, the mother-of-three took to social media to warn others.

"If a child had found it or run through it, the injury, it could have been fatal, it's right where the neck would go," she told 9News Perth.

"Have that safety talk with your children, tell them to have a look at their surroundings, make sure it's safe to play and you do so yourself."

The police and City of Rockingham have been notified.

The City says they undertake regular inspections of their playgrounds.