A friend received a border force seizure notice about a month ago, pretty sure that was re GoPure. They asked me if they should expect a visit from them or the police but I had a look at the letter and all it says is that the seizure is without prejudice to any further action. So it's possible but could just be a form of warning. The letter said 200 grams had been seized. Most of the letter dealt with the procedure for challenging the seizure.