Yes there is mains power inches away. The original suspected master is on it's own in the middle of nowhere in an awkward corner. Maybe he moved it because it's easier to plug the power in? I must admit it's a lot more convenient now , but I'm concerned whether it will affect me adversely.
It sounds as if Openreach have wired it correctly and moved the master so that it is next to power sockets for the modem. This is ideal and should have no impact on your connection.
They did the same for me as my master socket was by the front door with no mains power anywhere near.
James BT Infinity 2
19/09/2012 - Sold 42/6 - Getting 49/8.5 - Sync 53 / 9.5 Mbps @ 470m approx
14 years of broadband (ntl: cable to BT FTTC) - Router: Asus RT-N66U - Modem: Huawei HG612 speedtest