Customs is cracking down on shipments of life-like child sex dolls that paedophiles are importing into Australia.

Border force officials have seized 18 consignments of child sex dolls sent from overseas since 2013.

The life-size dolls resemble children as young as five.

The life-size dolls, which resemble children as young as five and are sold wearing lingerie, have movable joints and come with heating instructions.

A child sex doll manufacturer claims they can be used to help paedophiles control their urges.