Let me explain something very basic about civil service pensions. There is no pot. It's essentially a Ponzi scheme*. Things may have changed since my day but there wasn't even a contribution as in normal pension schemes. It was effectively a salary sacrifice scheme which meant that the salary, and hence the final salary, and hence the pension based on the final salary was less than if it had been a regular contributory scheme. But I digress. There is no pot. Like any Ponzi scheme pensions are paid out of current income, in this case tax.
As there's no pension pot could you explain how it could have been stolen?
For completeness, everyone else's retirement pension operates in the same way. National Insurance doesn't build you a pension pot, it's just a form of taxation. HM Treasury has a dread of taxation being ring-fenced in this way. So much so that they coined a word for it, hypothecation. A hypothecated tax sounds so alarming nobody who didn't actually know what it means would want it. Just as NI payments don't go directly and accountably to running pensions, NHS etc because that would be hypothecated, so Vehicle Excise Duty doesn't go to building and maintaining roads.