I'm guessing it's similar to here in Sweden where at some points in certain investigations you are obliged to divulge information or be faced with charges of obstruction of justice. What you can do in that case is remember as little as possible, simply repeating "I don't know" has been enough to not catch any charges as you are technically helping the investigation to the best of your ability.
However if you are certain that the investigation is about you SHUT THE FUCK UP.
However if you are certain that the investigation is about you SHUT THE FUCK UP.