The CWGC cannot search for remains and will only collect them when they are discovered. I have spoken with their Exhumation Officer based in Arras as well as one of their senior executives.
The CWGC collects the remains (bones) and any other items that assist in the possibility of identification. The other items discovered with the remains get thrown back in the hole unless someone present takes possession, legally or otherwise. When a nationality can be determined, the respective government is advised and the remains are stored in the CWGC secure storage facility in Arras. The government then decides whether the find is to be made public via the media (not the CWGC). The government can then take possession of the remains, generally for DNA or scientific investigation. If taken away, the remains are returned to the CWGC for burial. If the remains cannot be identified as being any particular nationality, the remains are held and reburied by the CWGC as an unknown without consulting any governments.
The police, CWGC and the local Mayor always have to be advised upon discovery. The Police, the CWGC and the Mayor consult. Once the Police are satisfied it is a WW1 casualty, they are finished and leave. They do not secure the area and as such, if the CWGC do not lift the remains on the same day, then they are left exposed (maybe under a sheet of corrugated iron) overnight. This is unfortunalety where the grave robbers (I just spat on my carpet) do their filthy work. Word spreads like wild-fire and "secret" discoveries are raided during the depths of the night.
Now, possibly in early June, I am going to re-discover the remains of a British soldier that has laid, following his original discovery, for some 25 years. I will not be alone and the discovery will only be done with the local Mayor's and the property owner's permission. But, if he is there, and if the CWGC is not out on the same day, I am taking out a blanket and standing watch....no mongrel bast.rd is going to get near him during the night. If I can get a qualified archeological person to be with me, all the better. BUT, the smaller the group, the better, as he is said to be beside a frequently used road. I hope the CWGC does not turn up with a hessian sack! His re-discovery will be done with a lot of care.
My hope is that this brave soldier can be returned to be with us, buried in a known place, and buried in a dignified manner.
If you want someone to stay with him overnight, or just want some company, i will oblige.