The article said that there was a similar container also missing. It also said that the contents were not harmful to the public, or something to that effect.
Remembering words to old song: "Do you believe like I believe......" That would be a traditional response. It's like a hospital telling you to come to the hospital because your loved one is seriously injured, when in fact they have already perished, but will confront you with the truth when they can control the situation.
If the contents are harmless, then why not publish the contents and alleviate fears? It may be nothing, but then again.......