Defra trials gassing as a badger cull option
Defra says no live animals will be used in the trials.
Defra has revealed it has been conducting trials to determine the humaneness and efficacy of gassing as a badger culling option since summer 2013.
Information about the trials has been published online following a freedom of information (FOI) request.
No animals have been used in the investigations, according to Defra. Preliminary tests have been carried out to investigate the dispersal of carbon monoxide in a sett environment. Trials will not involve the use of active setts or testing on live animals.
Nitrogen oxide foam has also been used in an artificial structure but this work is "not being pursued", Defra says.
The aim of the investigation is to determine whether humane and effective outcomes could be achieved using gas in real setts.
Trials are still ongoing and it is currently unknown how long they are expected to last. Defra is withholding the location of the trial to protect the safety and security of staff.
Pilot badger culls in Gloucestershire and Somerset last year aimed to reduce the badger population by 70 per cent as part of the Government's plan to eradicate bovine TB. However, shooters in both areas failed to meet their targets.
Furthermore, a report by an independent expert panel (IEP) revealed the culls failed on both humaneness and effectiveness.
MPs voted against a roll-out of the culls to other areas of the country in a parliamentary debate in March this year. Culls are set to continue in Somerset and Gloucestershire, however, with improvements recommended by the IEP.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
