The gunman responsible for the Orlando massacre appeared in a documentary on the BP oil spill, filmed telling an undercover reporter that people cleaning up the spill "don't give a s**t".

Mateen, who opened fire at gay nightclub Pulse on 12 June, killing 49 people and injuring 53 others, was working as a security guard for G4S when he was captured on hidden camera by film-makers Josh and Rebecca Tickell for their award-winning documentary The Big Fix.

The documentary, which was filmed in 2010, showed Mateen standing guard at a facility in Pensacola, Florida, linked with the clean-up effort, USA Today reported.

Rebecca Tickell, asks Mateen if she can come in and speak to someone about the spill, to which he responded: "There's people out here but they're all scattered all over the place. There's no one really to talk to, like any supervisor.

"No one gives a s**t. No one gives a s**t here, everybody just gets out to get paid. They're like hoping for more oil to come out and more people to complain so they will have jobs. Because once people get laid off here it's going to suck for them," he added.

"They want more disaster to happen because that's where their money making is."

The documentary-maker then asked, "It's all about the money right?" to which Mateen responded: "All about the money, exactly."

It has also emerged that Mateen checked social media for updates of the shooting as he carried out the deadly massacre, typing in "Pulse nightclub" to Facebook.

The BP Oil Spill began on 20 April 2010 when an explosion occurred on the Deepwater Horizon rig in the Gulf of Mexico, killing 11 people, and leaking five million barrels-worth of oil, until the well was capped on 15 July 2010. BP agreed in July last year to pay $18.7bn (£13.1bn) in fines, the largest corporate settlement in US history.