Land agent entering rented unit with no notice

My neighbour is in a rental. It’s a unit in South Australia. He’s been here for just under two years.

Today I bumped into his land agent in our driveway. My neighbour wasn’t home at the time. She mentioned in our conversation that she had just done a surprise inspection and wasn’t happy with what she saw. That it was unclean and had bottles everywhere.

I got the impression that she had gone inside but didn’t see.

Question is- can she enter the premises for a “surprise inspection” with no notice given when he’s not home. 

Can she look around the front and backyard when he isn’t home with no notice given?

This is a week known real estate company. I also know he has been behind in his rent a little, but not sure if this entitles them to enter without permission.