Been searching high and low, there was none, but I finally managed to find out how:

Copy: /store/includes/modules/additional_images.php
To: /store/includes/modules/your_template/

Edit the file by Finding and removing the lines:

$large_link = zen_href_link(FILENAME_POPUP_IMAGE_ADDITIONAL, 'pID=' . $_GET['products_id'] . '&pic=' . $i . '&products_image_large_additional=' . $products_image_large);

$img_large = zen_href_link(FILENAME_POPUP_IMAGE_ADDITIONAL, 'pID=' . $_GET['products_id'] . '&pic=' . $i . '&products_image_large_additional=' . $products_image_medium);

$img_large = zen_href_link(FILENAME_POPUP_IMAGE_ADDITIONAL, 'pID=' . $_GET['products_id'] . '&pic=' . $i . '&products_image_large_additional=' . $products_image_large);

$script_href = ' href="'.$img_large.'"';