Road priorities

[checkers46]

can anyone define the correct priority at a junction for a right turning vehicle from a main road into a minor road and a right turning vehicle from the minor road into the mainroad.
The minor road has give way lines and triangle on road, the main road has a right turning box. If a vehicle had already left the right turn box from the main road does it have priority over the right turning vehicle from the minor road?

[sara3]

in a nutshell, yes!

[checkers46]

Ok thanks I mean it sounded obvious to me!
I was involved in an accident and the right turning vehicle from the main road into the minor road represents me and the other right turn vehicle from the minor give way road is the 3rd party.
The 3rd party is disputing liability. I have sent my insurers some detailed diagrams of before during and after impact, also some photos of the junction a day later with some reference examples of how the traffic was placed at time of accident.
Now the 3rd party is claiming I hit them, I can only imagine they are saying I must have cut the corner. The damage to my vehicle is within the rear quarter and door (3 door vehicle) Would the damage help the insurers to show who was at fault?