Dear Munro:
It is possible that the police has another matter on their mind regarding visiting your ex boyfriend. When you approached the police about him, they told you there is nothing they can do, that his behavior didn’t call for their involvement.
Maybe something came up, another matter involving your ex boyfriend, and now they do have a reason to visit him, and in that visit they will include your complaints.
I think it is best that you leave the matter alone. It is a good thing that he indeed ceased contact with you, and you did the right thing telling the police that indeed there has been no contact. You already protected him by telling this to the police.
And now, that there is no contact, which is what you wanted, keep it that way.
anita