CIMRM 415-416 - Tauroctony. Borghese collection, Louvre, Paris
The relief, which has clearly been restored, seems to have been taken apart since the CIMRM was published, and the cave filling removed.
The first image, from Wikimedia Commons, has the following description:
Note that this branch of the Louvre at Lens is in the Pas-de-Calais.
The item does appear on the Louvre-Lens website here:
There is a further image in Commons here with the following details.