298 Mr S.M. Bruce, High Commissioner in London, to Mr R.G. Menzies, Prime Minister
Cablegram 563 LONDON, 17 October 1939, 7.21 p.m.
FOR PRIME MINISTER MOST SECRET
I have just heard that the First Lord of the Admiralty  has this afternoon announced in the House of Commons that Royal Oak was sunk in Scapa Flow. This I was told on Saturday under strictest pledge of secrecy. I have made strong protest that this publicity was given without your having been previously advised.
The Admiralty at the moment mystified how submarine could have got in, as previously believed defences quite impassable to submarine.
So strong was this feeling doubts were expressed as to whether cause of sinking, which is not yet absolutely established though the Admiralty now say it certainly was a submarine. Gravest anxiety felt and for the present the fleet is being kept at sea.