Purchased a bottle of sprits in the Dufry Duty Free shop in Terminal 2 of Mexico City International Airport today.The bottle was not wrapped using resealable tamperproof bags instead the used doubled up carrier bags with a plastic cable tie. When questioned I was assured that this would be acceptable for UK customs. In fact it was not and I had my purchase taken off me when entering the UK.The very understanding lady from UK customs says that they often see this on flights from Mexico and she believed that staff selling duty free will skimp on the resealable bags because of the cost. Anyone else coming through the Duty Free area in Mexico City International airport demand a resealable bag if buying spirits or fragrance. I'm going to send an email to Dufry when I get home to make them aware of this practice by some of their staff. I watched others purchasing spirits have their goods wrapped the same way.