With the growing childcare costs for nannies contracted through agencies, Australian mothers were forced to pay nannies through the 'black market' or through online and referral by friends. Nannies taken through this unregulated approach were only paid $15 per hour.

The Parenthood Executive Director Fiona Sugden said while families can look for different options to hire nannies, families should prioritize for quality care.

According to an inquiry in 2005, evidence of child care black market was found to be approximately worth as much as $6 billion.

A spokesman for Australian Taxation Office (ATO) said while they were tracking cash economy industries like agencies for home care, the organization had not look into targeting nannies.

"There is nothing wrong with paying a nanny in cash as long as the householder meets their obligations for superannuation and pay as you go tax, and as long as the nanny declares the income," the spokesman said.

Acquiring nannies through the black market pose risk for the children for these nannies should have undergone required first-aid training and background investigation.

"We know our biggest competitor is what is referred to as black market nannies or cash-in-hand nannies,'' Petrina Fraccaro, general manager of Brisbane-based employment and training agency Charlton Brown told Courier Mail.

"They are just babysitters, watching a child - our nannies are educators, educating the child," Fraccaro added.

"Nannies need to be proud of their profession and standby the regulations in place to assist in the development of this industry,'' Anna Massie, founder of The Corporate Kid.

Danielle Robertson, Australian Nanny Association president, encouraged mothers to pay appropriate wages to a qualified nanny. A qualified nanny cost mothers $25 per hour.

"It keeps rates down but generally people are not qualified, not experienced and that is fraught with danger for the kids.We are pushing for professionalising the industry, because the cash economy is a big risky area," she said.

A nanny for Charlton Brown for six years, Laura O'Brien said qualified nannies were the safest option for children, the families and the nannies themselves.

"Using a registered nanny is more secure for both the nanny and the family,'' O'Brien added.