Defender TD5 110, 1st gear has disappeared!

Hi all.
I have a problem with the above Land Rover, it's an 03 model.
I can longer select first gear. The gear stick goes into position easily, whether the clutch is in or out or the engine is running or not. All the other gears select fine. There are no unusual noises coming from the gearbox, in fact it all seems to be working normally except there is no first gear anymore... It is a work vehicle and whatever happened happened when a colleague was using it not me. He brought it back to me and said 'Oh, and first gear doesn't work anymore' claiming he'd done nothing wrong with it, so I don't know what happened.
I'm going to have a look at the gear stick assembly this afternoon to see if anything is visibly wrong. I'd appreciate a few pointers on what I might be looking for.

Difficult to say, could be the grub screw on the control rod has come loose, you would need to take the turret housing off to see, but this would probably make your gear selecting generally sloppy.

Exactly the same thing happened to my brothers 110 with the R380 gearbox recently. Local garage said it would be easier just getting another gearbox which is what he did.
Nick.

Hmmm. Two extremes there. Thanks guys.

if gear stick feels to be working fine ie gets all other gears and moves fully into position hasnt a loose floppy feel then its likely dog teeth collar has sheared off first gear,it would be caused by a shock load