Thin grey line around placed element?

When I place certain .psd files a thin grey line appear around the border of the file. But not consistently and depending on the zoom level the grey line will be visible on only side or more – And I can't seem to see a pattern in when. 

The line is also visible when I export to a pdf with the same random behavior. 

The placed file do not have a stroke around it. 

Anyone know what can cause this and how to get rid of it?