Tomb of Sesostris (Senusret) II (1897–1878 BC) uncovered at Al-Lahun, Egypt. Sesostris II was likely the pharaoh whose dreams Joseph interpreted and who made Joseph a high official (Gen. 41). Although the announcement makes it sound like this is a new discovery, Flinders Petrie first excavated the tomb of Sesostris II in 1887–1888.
For photos of the pyramid of Sesostris II where the tomb chamber is located, see http://www.biblearchaeology.org/post/2008/07/Egypt-and-the-Bible.aspx.
See also, Bible and Spade, Winter 2005, pages 2–3 here: http://www.biblearchaeology.org/bookstore/product.aspx?id=11