ScrollView zoom leaving top, bottom margin

I have a scrollview with a nested image view, when I zoom the image enlarges as it should. However, if I scroll down the image I can go past the bottom of the image even though I have set the scrollview content size to the size of the new zoomed image. What I ideally would like to happen is when I scroll to the bottom of the image is to have the scroll view stop and not allow me to scroll any further. Similarly when I scroll left or right I don't want there to be any obvious margin appearing. Would be grateful for any help. class ViewController: UIViewController, UIScrollViewDelegate { @IBOutlet weak var scrollView: UIScrollView! @IBOutlet weak var imageView: UIImageView! override func viewDidLoad() { super.viewDidLoad() self.scrollView.minimumZoomScale = 1; self.scrollView.maximumZoomScale = 2; self.imageView.contentMode = UIViewContentMode.ScaleAspectFit; self.imageView.image = UIImage(named:"cecil.jpg" ) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? { self.scrollView.contentSize = self.imageView.frame.size self.scrollView.contentInset = UIEdgeInsetsZero; return self.imageView; } } I turned off bouncing in the properties - the image displays stops the scrolling when it reaches either side, but not from top to bottom which still shows a margin. When the device is in horizontal then the issue manifests from left to right.