It's not every day the police make a sudden guest appearance in your group chat.

Earlier in the week, 20-year-old Cardiff University student Lawrence Court received a fairly bizarre message on his phone.

"Hello, it's the police on Cameron's phone," read the message. "He is very drunk and we are dropping him home."

Court told Mashablehe and his friends were sceptical at first.

"We naturally thought it wasn't real and that Ron (the guy involved) was playing us," he explained.

You can tell from the second screengrab that people in the group weren't entirely convinced.

Then things escalated:

Yep: the police decided to prove their legitimacy with the following, spectacular photo.

"When the selfie came through we were in hysterics, it was so funny!" said Court. "Then it was a case of making sure that he was okay so some friends went to check on him!"

Court shared the screengrabs in a tweet on Tuesday afternoon, which has since gone viral in a big way.

This Tweet is currently unavailable. It might be loading or has been removed.

So what did the police do after they'd dropped Ron safely at home?

"We don't actually know and neither does Ron," Court said

"I assume they put him to bed and continued their shift!"

Good work, Cardiff police.