The footage purports to show Taliban fighters raiding the compound, now known as Shorab, in an attack which is said to have lasted around 48 hours and caused – the Taliban claims – “heavy losses” for “the enemy”.
The video is 30 minutes long and begins with a small introduction followed by images of the Mujahideen in training.
Richard Parry, a director and writer who spent six to seven weeks at Camp Bastion earlier this year as British and US troops prepared to leave the base, told Channel 4 News that the film looked “genuine”, but parts “look to be like a training video.”
Mr Parry, whose documentary Billion Pound Base: Dismantling Camp Bastion is due to be aired on Sunday on Channel 4, said: “Footage taken from behind the compounds is on the east side of Bastion. It could possibly be the main road… from Kandahar to Herat.
“Although I have spent some time on the east gate (which would be under a mile away), I have never looked back at the camp from outside – so I can’t be 100 per cent.”
He said his sources said there had been an attack on the base over the weekend.
Operations in Afghanistan have claimed the lives of 453 UK soldiers. The vast majority of the UK’s death toll came in the fight against the Taliban insurgency in Helmand, after British soldiers established a presence in the southern province in 2006.
Channel 4 News has contacted the Ministry of Defence for a response.