Swindon and Wiltshire Police and Crime Commissioner Angus Macpherson and Chief Constable Kier Pritchard have issued statements following the announcement by Det Sgt Nick Bailey that he is leaving the force.
The veteran officer suffered Novichok poisoning while investigating the attack on Sergei and Yulia Skripal in Salisbury in 2018.
Announcing his decision on social media, he said: "After 18 years in the Police Force I’ve had to admit defeat and accept that I can no longer do the job.
"I wanted to be a Police Officer since I was a teenager, I couldn’t envisage doing anything else, which is why this makes me so sad."
Mr Macpherson said: “I would firstly like to thank Nick for his service and dedication to Wiltshire Police.
“Nick found himself at the centre of an international, criminal incident which not only affected his health but I am certain changed the course of his family’s lives too.
“The events in Salisbury and Amesbury back in 2018 remain unprecedented and Nick, himself, has found himself in a situation that no other police officer in this country has been through.
“I know that the force has offered as much welfare support to Nick as possible but I hope today brings Nick and his family some sense of closure and allows them to start to look to the future.
“Each day, our officers, staff and volunteers do all they can to best protect the public and Nick symbolises that dedication and sense of public duty.
“I wish Nick and his family the very best in the future.”
The Chief Constable said: “I have known and respected Nick for many years as a dedicated colleague and detective.
“Understandably, Nick and his family’s lives was turned upside down following the events in Salisbury back in March 2018.
“Nick was one of the first officers involved in this incident when he was exposed to the lethal nerve agent Novichok.
“These shocking and unprecedented events changed his life and his family’s lives significantly.
“It is impossible for any of us to fully understand the impact this event has had on Nick and his family, and the sacrifices they made in trying to come to terms with the situation.
“Nick’s commitment to the service has never been questioned and this was further illustrated by him making several attempts to return to full duties.
“He represents the dedication and determination that all of us want to see in police officers across the country. Day in and day out, officers put themselves directly into harm’s way in order to help and protect others.
“Nick should be incredibly proud of all that he has achieved and will always be considered to be part of the Wiltshire Police family.
“I am sure that as one chapter closes, another opportunity will open up for Nick.
“He has been an outstanding officer and I wish him and his family the greatest success for their future.”