With this in mind, Australian Federal Police and Anti-Slavery Australia have launched a campaign to prevent forced marriages that will be rolled out in the bathrooms of the domestic and international terminals at Sydney Airport from Tuesday.

The AFP defines a forced marriage as marriage without a person's free and full consent because they have been coerced, threatened or deceived.

Posters and digital screens explaining the illegality of forced marriage in Australia and displaying avenues of support will be placed in the bathrooms at Australia's busiest airport over the next six months.

Bathrooms were chosen as the best place to display the information as they are "often the only places in an airport that passengers at risk of being taken overseas for forced marriage may be on their own", the AFP said in a statement.

The AFP said the number of forced marriages being referred to police has increased as awareness of the issue grows.

There were 91 reports in the 2018/19 financial year compared to just 11 in 2013/14, when forced marriages were officially made illegal under Commonwealth law.

"Supporting people in Australia who are at risk of forced marriages - particularly vulnerable teenagers - is crucial, as we recognise that disruption and deterrence can have a far-reaching and lasting impact in our communities," AFP Assistant Commissioner Debbie Platz said.

Anti-Slavery Australia director Jill McKeough said connecting with the right support services in forced marriage scenarios - such as those explained on the posters - was crucial in helping people escape situations of despair.

"It is vital that people get help before they are forced to go overseas for a marriage they don't want," Ms McKeough said.

Some 44 million people pass through Sydney Airport each year.

Australian Associated Press