Apparently the ship didn't even have a tether, what they picked up was from the surface. The pinger has a range of 2km, the sea is 4km deep. Whales and all sorts of equipment can be detected on this frequency. The signal was picked up once for an unspecified time and not found again since. It is an unconfirmed report on a Chinese twitter account. UK ships detected a signal earlier in the week but it was ruled out before leaking rumours because these things need checking. The ship isn't even in the search zone. FARSE!