I personally dont understand why these companies want to know the ins and outs of your arsehole!!
Why would the need to know your passport number and have copies of every page of your passport plus your NI number before you even got the job!! This is seriously a security threat or is it just big brother? I remember filling an app out for a middle eastern company that wanted details of my families passport numbers, seriously is that necessary how about I tell them my bank details whilst im at it!