Not theft
An AC spoke : "Did they take his computers/server away because that may be theft if FACT/trading standards have it. If not and he has not been charged the police should return it and he can go back on line in the clear"
Unfortunately it wouldn't be theft, as among other things to you need to prove the following points for theft :
- Dishonesty : The plods that took it can say that based on the information they received they had reasonable grounds to think that the computers may have evidence of a crime on them. Thus there is no (legal, anyway) dishonesty on their part.
- Intent to permanently deprive : Even if they could be proved to be dishonest, there is no intent to permanently deprive the owner of the property, as the Police will state that their intention is to return the property at the end of their invesitgation. This may be a LONG time from now, as even though the chap was released without charge (or was he just given Police Bail?) the invesitgation may last much longer (and of course the Police may decide to charge him at a later date if they discover any actual evidence of crime).
Of course, if it turns out in due course that the Police didn't have sufficient grounds for the arrest/search/seizure in the first place, then their actions after that will most likely be illegal and he would have grounds to complain/sue. However an arrest just has to be based on "reasonableness" rather than absolute guilt, otherwise you couldn't arrest someone until they had been found guilty by a court! This all seems unreasonable to us, but the Police have got away with a lot worse than this under the banner of what is reasonable.
As an aside, I'm an ex-plod, and crap like this (particularly in the area of IT related crime) was one of the reasons that I quit the force.