In a social media post police slammed those behind the burglary in the Riverview area at the weekend.
"Yet again we are disgusted, as another vulnerable person in our community has had their house broken into and their treasured possessions stolen by someone who is not wanted or needed in any community, they are parasites with no useful function all they do is cause hurt and pain to valued members of our community," they said.
"Last night one of these parasites broke into a home in the Riverview area of Moneymore, and stole several items one of which is similar to the famous Princess Diana ring, That Prince William later gave to Kate when he asked her to marry him. The ring has diamonds on the outside and a sapphire in the middle.
"Let’s see if we can make this ring too hot to handle for the little parasite our maybe encourage them listen to their conscience and have these items returned to their owner who cares deeply about them."
Anyone who can help trace those responsible is asked to contact police on 101 or contact crimestoppers on 0800 555 111.