Give an account of the worst break-in in the annexe?Did the police actually reach the secret door?

There is another burglary, with complications this time. The intruder had a skeleton key or a duplicate and did not have to force his way inside. Plus, he was scared off when he heard Mr. Van Daan. This is unfortunate for the residents of the annex, because that person may report them. It would be especially unfortunate if the burglar is one of the warehouse workers. I don't think the police investigated the secret door in any suspicion.