Nah. We can hypothesize very conservatively based off of what we knew existed in the 1960s-- agency issued suicide pills, and remotely detonated explosive molar implants to prevent squealing (albeit with a quite short range because of technical limitations at the time).
Well, suicide pills are certainly possible. The question is whether any agencies use them. To that end I have no idea.
I do question exploding molar implants, however... that seems like something straight out of a cheesy spy movie. If those do exist I'd love to see what the idea in using them was, because that's kind of funny.