They weren't by any chance like these?
If so, they are not just in Hampshire. I wonder what the round thing is on the fitting? 100 LEDS and as you say very bright. The Hi-bay fitting is sort of ideal for LEDS as you can get a large heatsink in the volume of the enclosure. The rest of the enclosure will be in in free air in the canopy roof void so can dissipate the heat.
Is this the beginning of the end for the "traditional" Lo/Hi-bay fitting? Come to think of it, the fitting is the same sort of size as a ZX3 or large Iridium/Sapphire. Petrol station forecourts are around 5m tall, could a modified fitting suffice at 8m?
I wonder how much power they consume? 100 LEDS say even if 1w each (and I suspect they are more than that) and say 50% efficient (which is not unreasonable for a LED) would imply 200w so where is the power saving per fitting? There is only a saving if less luminaries are used, which wasn't the case for the ones I pictured.