A prisoner posted a review and pictures from inside his "4-star" police cell.
Christian Willoughby described the staff at Grimsby Police Station, Lincolnshire, as "pleasant enough" and added: "Had my own on-suite (sic) room and butler".
He shared a series of photographs of the food and his room on Facebook after being arrested for what he described as a "misdemeanor".
When asked how he managed to get his phone into the cells he replied "it's an iPad".
He posted a picture of a tray of food on Wednesday morning and said: "2 sausages floating around a runny sauce with a threw (sic) diced potatoes thrown in. Lovely."
Later the same day he shared another six photos and wrote: "I've given this place 4 stars. It's the all day breakfast that lets it down really.
"Apart from that the staff are pleasant enough. Had my own on-suite (sic) room and butler ... Who would come with tea and newspapers.
"Room was nice, the minimalistic idea was a nice touch. It was secure and safe ... Quadruple glazing and security door. Ideal place for winding down after a hard day. I'd definitely come back."
Humberside Police said the breach of security is being investigated.
Chief Inspector James Glansfield said: "The force are aware of pictures apparently of the Grimsby Custody Suite on social media.
"These appear to have been taken by a prisoner while in custody on Wednesday March 9.
"We take any such breach of security and detainee safety extremely seriously and will be carrying out a review of our detainee management to identify any lessons learned and prevent further reoccurrences in the future.
"The force's Professional Standards Branch are investigating the circumstances of the incident."