"From what we gather, he made no attempt to gain entry to any other room in the house. This offender made no attempt to steal any property, which has indicated he didn't go there with the intention of burglary and was there for one reason."
The offender spent about 15-20 minutes inside the girls' bedroom before he took off down the street.
Former Bay of Plenty Detective and host of the crime-fighting television series, Graham Bell, said: "Any indecent assault on a child is really bad news and it worries us that this guy might strike again. The guy needs to be stopped and he won't stop until he has been caught."
If you have any information about who the offender is, contact Tauranga police on 577 4300 or anonymously call Crimestoppers on 0800 555 111.
The show will screen at 7.30pm on TV 2 tonight.