Abused daughters' parents front campaign

They've campaigned to meet the Pope and spoken out against horrific abuses within the Catholic Church that destroyed two of their daughters' lives.

Now Anthony and Christine Foster want to warn other parents that the "insidious" sexual abuse inflicted on two of their three young girls during primary school could happen to anyone.

The Melbourne couple, who found themselves excluded from a meeting of sexual abuse victims with Pope Benedict XVI during his visit to Australia last year, are the face of a new advertising campaign warning parents to "Wise Up" to child sexual abuse.

Their firstborn, Emma, committed suicide in January last year at the age of 26 after a long battle with drugs.

She had been repeatedly raped by parish priest Kevin O'Donnell over about four years, starting in her first year of primary school.

Her younger sister, Katie, was raped by the same priest and now requires 24-hour care after she was hit by a car while drunk at the age of 15.

Mr Foster says parents need to be attuned to signs their child may be being "groomed" or suffering at the hands of a pedophile, because the "insidious" nature of sexual abuse makes it hard to detect.

Children are silenced by threats from their manipulative tormentors and find it impossible to speak up, he says.

"It can happen under your nose, without you knowing, and without you knowing for a long time," Mr Foster told AAP.

He said the new campaign by child protection agency Child Wise, including a television advertisement featuring the Fosters, aims to highlight how a "normal, average" family can be torn apart by sexual abuse.

In the Fosters' case, Emma turned to drugs and self-harm while Katie turned to alcohol, both with catastrophic consequences.

"You go from kids who look absolutely gorgeous, having a perfect life, to a heroin addict who dies beside her bed on her own," Mr Foster says.

At 13, Emma became anorexic, started cutting her wrists and took overdoses of painkillers and other off-the-shelf medication.

After she began seeing a psychiatrist, the Fosters learnt she had been abused by a parish priest who visited their children's Catholic primary school in Melbourne's southeast.

Looking back, Ms Foster said there were some signs that Emma was distressed as a young child - she began wetting the bed and had regular anger headaches.

She said the couple had tried to protect their children but the harm was done in a place where they should have been safe, by a trusted person.

"That's not taught, it's like a big black hole that parents fall in," she said.

"That's how I feel about myself, because I did protect my child, we did. We did everything."

The Wise Up campaign points to an alarming incidence of child sexual abuse, with one in four girls and one in seven boys affected.

Child Wise child protection manager Karen Flanagan said the Fosters' experience showed sexual abuse does not discriminate.

"While we know sexual abuse happens a lot to marginalised families, the point is it can happen to anyone," she said.

O'Donnell was jailed for just over a year in 1995 for a range of sexual offences against other victims and died in 1997.

The Fosters battled with the Catholic Church for eight years to be compensated for Emma's abuse and received a substantial payout three years ago.

The couple travelled to Sydney last July seeking to confront Pope Benedict and Cardinal George Pell to campaign for the Catholic Church to offer victims of sexual abuse unlimited support, rather than the maximum $50,000 compensation cap, but were denied a hearing.

For more information on the Child Wise Up campaign, including a booklet by Christine Foster visit www.childwise.net.