Engine locked

[squeak]

Having completed work on the camshaft and bearings.
Just about to grind in the valves.
Engine is now locked solid.
Engine has been in every position possible while working on it.
Is it possible for the oil pump to seize ???
Help much needed

What have you done since the last time that it turned?

I once had this symptom which was cured fortunately after finding the sump bolt centre rear was touching the flywheel. Hope this is your trouble, cheers  Russell