Added to our disavow file.
We regularly go through our link profile and remove 5% of the stuff we're not happy with, or looks suspicious. This one somehow slipped through for a long time. White text, white background, exact match anchor text. I asked around the office, nobody knows how this link happened. I find it hard to believe anyone would have done such thing internally. It's visible in our database as an automated Google Webmaster Tools import from 2011.

http://teresagambaro.com/2011/06/visiting-the-year-seven-students-at-st-margarets/