Qt: QWebview not displaying jpg, gif, png images on another machines

Question

Today I came across a very strange error with QWebView which I cannot resolve myself.

I included a QWebView widget in my application. When I set a URL or a piece of HTML code to display (with QWebView::setUrl() or QWebView::setHtml()), it works very well on my machine. It also works on all machines that have Qt installed, but not on those without it. I compiled a release build and included all necessary libraries as shared (QtWebKit4.dll, QtNetwork4.dll etc.), so I guess my error lies in that I forgot to include some libraries.

If anybody has already had such an error, I would be very grateful for help!