A video emerged on TikTok showing the Prime Minister and his family allowing their pet to roam freely in a Royal Park - the exact location of which is not clear - next to a sign saying dogs must be kept on leads.
A Met spokesman said: “We are aware of a video showing a dog being walked off the lead in Hyde Park.
“An officer, who was present at the time, spoke to a woman and reminded her of the rules.
“The dog was put back on the lead.”
Downing Street has not commented.
What are the rules for walking dogs in the Royal Parks?
The Royal Parks are eight green spaces across London and dogs can be walked off leads in places but not everywhere.
The website says: “Dogs are welcome in all the Royal Parks although there are some places where they are not allowed or must be kept on a lead.
“These are clearly indicated within each park and are usually ecologically sensitive sites, deer parks, children’s play areas, restaurants, cafés, and some sports areas.
“When walking your dog in the Royal Parks, please respect the wildlife as well as the other park users by keeping your dog under control.”
What are the rules for walking dogs in general in London?
Dogs are allowed to be let off their leads in the UK while walking in a safe area and where there are not signs warning owners to keep them on a lead.
However, owners are advised to take caution when allowing dogs to roam freely. This should represent a judgement call by the owner based on the dog’s responsiveness, temperament, and experience.
Some areas operate public-space protection orders on this matter and owners should look out for warnings of PSPOs - as falling foul could result in a fine if the rule is broken.
A statement from the RSPCA reads: “Make sure you know where your dog is at all times. If you're letting your dog off the lead, be confident there are no livestock nearby. Be sure that your dog will return to you promptly on command and, if in doubt, keep them on the lead.”