The number of children who need to be cared for by their grandparents is growing.

A new national support office will open today for the Grandparents Raising Grandchildren Trust, to help with the increasing demand of children in need.

The trust is there to assist grandparents who now take care of their grandchildren due to the parents having issues with crime or drugs.

Trust chief executive Kate Bundle told Mike Hosking that it's a sad truth the numbers are rising.

"In the last year, we have had 721 new member families join us for our support. And we know that the main reason why they are joining us for support is because of parental substance abuse"

LISEN ABOVE AS KATE BUNDLE SPEAKS TO MIKE HOSKING