Since 8pm on Saturday evening we were seeing high latency and packetloss to some IPv6 addresses hosted by he.net (Hurricane Electric). At around 10pm we change out outbound routing and latency reduced to normal levels.
The routing change we made moved the traffic from our LONAP peering port in Telehouse to our LONAP peering port in Equinix LD8. This suggests the problem is either within LONAP, or more likely within HE's network.
Service remains stable with our routing over LONAP slightly adjusted (as above).