Undue influence was made illegal in the Adoption of Children Amendment Act 1964. It was defined as something done by a person who: ' uses or threatens to use any force or restraint, or does or threatens to do any injury, or causes or threatens to cause any detriment of any kind to the mother of a child, with a view to inducing the mother to offer or refrain from offering the child for adoption'. The penalty for using undue influence was two hundred pounds or six months' imprisonment at the time the Act was passed. However, this and other amendments in the Act did not come into effect until 1 May 1970. Undue influence remains an offence under the current adoption laws in Western Australia.