Anyone with any information should contact Det Sgt Alan Clements via the 24-hour Police Enquiry Centre on 101.
If you don't want to speak directly to the police, you can contact the independent charity Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org. No personal details are taken, information is not traced or recorded and you will not go to court.
More top news
A Which? investigation showed that users of Virgin Media's Super Hub 2 router could be at risk of a hacking attack.
A memorial to honour the service of millions of men and women from Africa and the Caribbean during the two world wars has been unveiled.
New figures show the government spent nearly £140,000 pursuing a case against a father who took his daughter on holiday during term time.