Thanks for all the info.
When a business listings is made live it gets pushed in to the respective push-collection with the following url - domain/business/business-listings/businesses/page-name
We imported a large number of business listings from our old site, but found out afterwards that there was a duplicate.
This duplicate didn't get a web path, but was made live and pushed to the collection.
This appears in the results screen as domain/business/business-listings/businesses/ so when a user selects them it returns a blank page.
We have since fixed the web path of this asset, but if we put the page Under Construction, it isn't deleted from the push-collection because it cannot find the respective url and therefore the web path doesn't get updated when the asset is made live!