A police horse tragically died during the Notting Hill Carnival over the weekend.
The Metropolitan Police confirmed a post-mortem was underway into PH 149 Sandown after the 14-year-old chestnut gelding collapsed on Sunday.
PH 149 had been gifted to the Met Police in 2015 and was praised for his ability to help new recruits get used to life as a police officer.
In a tribute, the Metropolitan Police said: "He played an integral role in helping to police London. He was one of the Met’s most experienced horses, with an impeccable seven year police career.
"PH Sandown was gifted to the Met in 2015 and his good nature quickly won over officers. He was the go-to horse to help new officers grow in confidence as they went through their training.
"A pro at policing all types of events across London, he demonstrated his bravery and courageousness at numerous football fixtures whilst also being selected to perform at the Mounted Activity Ride at Olympia, and the Mounted Musical Ride.
"Police horses are working animals, but PH Sandown was also an affectionate character who was full of personality. He loved his food and was always nuzzling in pockets looking for treats.
"PH Sandown was a massive part of the Mounted Branch family and was loved dearly. He will be sorely missed by all."
While it is too early at this stage to determine a cause of death, a post-mortem is under way.
The Metropolitan Police said that by 7am on Monday there had been 38 arrests for "a variety of different offences" at the carnival.
Officers said a police horse died on duty during the carnival after collapsing at about 9pm on Sunday.
The force said it was too early to determine the cause of death, adding there will be an investigation.