I spoke with the DI who told me they were acting on good information from a reliable source. They Smashed the main entrance door in to gain access to the flats which share a common entrance. They then smashed in the wrong flat front door (which happened to be vacant) before smashing in the door to the tenants flat. They told me they were acting quickly to seize evidence that was allegedly in the tenants flat. This was on the Monday but the bank robbery was on the previous Friday, so not that much of a rush. The police have agreed to pay for the wrongly smashed in door but not the common front door or the tenants door as that was the correct address. Although they are not charging him and have returned his cash.
So, just for clarity if the Police believe you were involved in a bank robbery they can forcefully gain entry and search your property with out a warrant.