For the last five years or so, several 3D data hiding algorithms have been developed. Few of them proposed methods to hide data in 3D objects without changing the position of vertices in the 3D space. In this paper we propose a new approach of data hiding in 3D objects based on the minimum spanning tree (MST). This method is lossless in the sense that the positions of the vertices are unchanged. The method is blind and does not depend on the ordering of the data in the files. Moreover the embedding capacity is significant and can be as high as $2.5 \%$ of the size of the 3D object.