Hi Lepardess & welcome to WATW
Originally Posted by lepardess
The body is approximately 13 cm in length. It has 6 legs that are hairy like a tarantula ... The body looks like one of those Columbian roaches. They get to be upwards of 5 inches long.
I'm a bit worried about your concept of size - or maybe mixing up metrics or erroneous conversion calculations...
I have a bit of a hard time imagining any non-prehistoric/non-tropical beetle of 13 cm (over 5 inches) and all I can find about "Giant" cockroaches seems to max out at 9 cm (3.5 inches).
Does the 13 cm maybe include antennae and/or tail appendices? Or are you sure it's just sheer body size (top of head to tip of tail, not including any antennae/appendices)?
Talking about that: Does the animal even have antennae, huge pincers or tail appendices or the like?
And what about the hairy legs? Are you positive it's 'hairy like a tarantula' or might it also have been 'little spines' (such as on many roaches or so).
As you mentioned spider like features a few times: Could it be that it just has two legs amputated? And any idea on the head shape or maybe even the number of eyes on it?
Just trying to get my head around it....
@Others, just for reference: Same question was asked here on WAB
earlier, so some suggestions might still pop-up there too (although it's more of a non-British WATW-topic)
Another interesting puzzle ...
P.S. I don't think it really fits the description but maybe have a look at Macrodontia cervicornis
... other than that I'm very much doubting that it would be a beetle. Maybe some tropical (true) bug ....