Time complexity of agglomerative hierarchical clustering functions?

Does anyone know the time complexity of MATLAB's hierarchical clustering functions like "clusterdata" or the 3 functions "pdist", "linkage" and "cluster" (when used together)? I tried reading the source code, but the computations seem to be done in mex-files which i can't access.

Or, does anyone know if the algorithm used by MATLAB has a known time complexity like the CLINK or SLINK algorithms? The MATLAB documentation has not shed any light on this.