In the context of espionage 'sour milk spy' is a phrase that denotes what happens when a spy is discovered and rather than being taken into custody, he is fed information that is false. The intention is that the spy will then pass that information along and the buyers will discover it is false, thereby creating a situation where they cannot trust information they'd been given previously. Such a scenario can spoil all that was learned.
Canadian Spy: Suspect Information
Delisle is an intelligence officer who had access to secret information and is accused of selling some of it to the Russians from July of 2007 until mid-January of 2011. However, Canada's Post-media
news says they learned that when the Navy discovered Delisle's alleged activities they turned him into a sour-milk spy by feeding him, without his knowledge, false secrets.
“This was done by the book - sour the milk so you confuse the other side,” the former counter intelligence officer Michel Juneau-Katsuya told Post-media news in an interview. Juneau-Katsuya, Post-media said, got his information from members of the armed forces intelligence who are close to the case.
Sub-Lieutenant Delisle: "Breach of trust"
Delisle worked at the communications and intelligence section in Halifax called the Trinity
section and the Halifax Chronicle-Herald reported that Department of Defence sources said the Trinity section "is a multinational operation with access to secret data from NATO countries." Juneau-Katsuya speculated it was information on NATO Russia would have been interested in.
Delisle has been charged with a breach of trust, communication of safeguarded information and attempting to communicate safeguarded information. He was said to have met with those he sold information to in Ottawa and Kingston in Ontario and in Halifax and Bedford in Nova Scotia;
Delisle lives in Bedford.
Keeping in mind that in the world of counter-intelligence that what you are told may not be what is real, there is the possibility there was no 'sour milk' operation but that, in an attempt to sow the seeds of doubt in the buyer of the information after the fact, Canadian intelligence has suggested to media, through Juneau-Katsuya, that misinformation was covertly given to Delisle.
Delisle is behind bars in Halifax and will have a bail
hearing on Jan. 25.