I've worked out how to get the advanced diagnostics from BT's checker (I'm in a remote office) and I think I need to get our IT guy to investigate:
Download speedachieved during the test was - 2.65 Mbps
For your connection, the acceptable range of speedsis 60 Mbps-77.44 Mbps .
IP Profile for your line is - 77.44 Mbps
2. Upstream Test: -provides background information.
0 Mbps 20 Mbps
Max Achievable Speed
Upload speed achieved during the test was - 1.05Mbps
Upstream Rate IP profile on your line is - 20 Mbps
I could only run the test from a VM so ignore the really bad speed. But the profile suggests there's nothing wrong with the line. It's either the ISP, the exchange or the router he's using. Shouldn't be the latter though because I think he's gone with the router Eclipse sent.