Arrested under Suspicion of deception under misrepresentation

I have question regarding an arrest made on suspicion of false misrepresentation under the Fraud Act 2006 which governed under UK Law. I am trying to be as concise as possible without having to write too much but if I may, briefly outline the case facts, then it may make it easier to assess the question.

My brother, Amir has been arrested on suspicion of obtaining goods by false misrepresentation under the Fraud Act 2006. This is on the basis on a parcel-delivery man giving a description of him being the one that had signed the receipt of delivery for goods in someone else's name (that name being the tenant living in the house who the package was for). Amir has two witnesses that can prove he did not hear or answer the door because they were present in the house on that morning.

Also a full house search was conducted by the police in hope to find the parcel that they belived Amir had but nothing was found. We believe that either the tenant in the house has provided the parcel driver with a photograph or the parcel man may have taken it himself and provided this description based on previous visits to the house to deliver packages. He has been getting many text messages from the tenant (who has since moved out) who keeps telling him that things are going to become worse if he doesn't own up to signing for the parcels. Amir is 100% innocent but the police are trying to trap him to convict him.

The police intend to conduct a photo id viewing screen for the parcel man to identify the person who has signed for the package. In the unlikely event that Amir is identified by this parcel man either through the aid of the unreliable source being the tenant providing a picture to make identity easier.

What amount of evidence would substantiate the police to make a charge and refer the case onto the Crown Prosecution Services (CPS)? I am unaware not being experienced in this field, on the threshold requirement that maybe set. Of course cost implications I assume would be taken into account based on whether it would be worth while convicting on small amount of evidence. Also, would this be sufficient evidence to make a charge for conviction under this law? Is there anything you could recommend or legally that would add strength to his case about these texts messages being received from the tenant who made the claim to the police? If you get back to me in regards to these question, this would be very helpful and really appreciated. I am in desperate need for all the help I can to get him free from this mess.

If anyone has any experise in this area of law, any help would be much appreaicate. Thanks in advance