Google said Sunday it would explore why the picture of Britain’s Second World War leader Winston Churchill disappeared from a top search results list of former U.K. Prime Ministers, during controversy over his record on racism.

The search giant said the photo’s removal from its horizontal list atop search results for former British Premiers was due to an automatic update and “not purposeful”, but apologised “for any concern”.

It noted that the issue only applied to its so-called “knowledge graph” listing and that many images of Churchill were still easily found on its search engine. “We’re aware an image for Sir Winston Churchill is missing from his knowledge graph entry on Google,” the firm’s search liaison arm said on Twitter. “We apologise for any concern. This was not purposeful & will be resolved. Images in such panels are automatically created & updated. During an update, they can briefly disappear.” The statement added his photo would be restored.