Reqs, Britain's longest-serving fire investigation dog, announced on BBC Breakfast today (Friday, July 28) that he is retiring from Hertfordshire Fire and Rescue Service.

The black labrador has been using his phenomenal sense of smell to help the fire service for almost 11 years, seeking out the presence of accelerants like petrol at the scenes of fires across Hertfordshire.

One of his final jobs was at the scene of the recent fire in Baldock industrial estate, where he was present alongside his "protégé" Loki as the fire service sought to uncover the cause of the blaze.

The Comet: Reqs as a puppy, before embarking on his career as a fire investigation dog.Reqs as a puppy, before embarking on his career as a fire investigation dog. (Image: Hertfordshire Fire and Rescue Service)

Reqs is now 11 years old, and joined the service in 2012 when he was just one.

Since then, he has attended around 500 incidents and helped provide crucial evidence in high-profile investigations, including for arson and murder.

The detecting abilities of Reqs and his handler Watch Commander Nikki Harvey have resulted in more than 250 years behind bars for convicted offenders.

Nikki said: “We are called to the scene of any serious fire that crews believe to be deliberate or suspicious, or where the cause is not immediately known, especially if there has been a fatality at the scene.

“Reqs gets involved as soon as it is safe. I’ll go through the scene first to check that it has properly cooled down with no visible sign of smoke or embers and that there aren’t any hazards that could harm him.

"He gets to work using his best tool – his nose – to locate any potential accelerants like petrol that might have been used to deliberately start a fire.

"That’s when the human fire investigators like myself can take a closer look while Reqs enjoys a reward – his favourite tennis ball!”

Reqs has amassed more than 10,000 followers on social media (@HertsFireDog on Twitter, Facebook and Instagram), alongside his protégé Loki, who will now be taking over Reqs' senior role.

The Comet: Reqs has helped at around 500 different incidents during his long career.Reqs has helped at around 500 different incidents during his long career. (Image: Hertfordshire Fire and Rescue Service)

Reqs is hugely popular with Hertfordshire residents too, through his regular appearances at fire station open days and countless visits to schools and clubs.

He has also brought comfort to many families who have sometimes lost everything in a fire.

“His interactions with children, especially those who have had fire in their home, leaving them quite frightened, can be therapeutic.

The Comet: Reqs (right) with his handler Nikki and protégé Loki.Reqs (right) with his handler Nikki and protégé Loki. (Image: Hertfordshire Fire and Rescue Service)

"The distraction of stroking him and throwing him a ball can give comfort and reassurance to those affected by traumatic incidents,” said Nikki.

After years of hard work, Reqs will now be putting his paws up as Nikki's pet dog, and will still attend community events alongside Loki - especially if he gets the opportunity to steal a few sausages from the barbecue.

The Comet: Reqs investigating at the scene of a fire.Reqs investigating at the scene of a fire. (Image: Hertfordshire Fire and Rescue Service)

Nikki said: “I’ll miss the nice cuddles he gives at the end of a job, especially if we’ve been to an upsetting or distressing incident.

"He’s my best mate and I love him to bits – while it’s the end of an era in some ways I’m so pleased he’ll still be around and part of our very special community, and I know that Loki will carry on doing a great job in his paw-steps.”