New research has chillingly suggested we actually know when we're dead and are aware of what's happening around us.

The spine-tingling reason is, according to one study, because the brain keeps functioning, suggesting a person's consciousness keeps working.

So even after the heart has stopped beating and body movements fail, it has been suggested people are essentially "trapped" inside their dead body with the brain still functioning.

Cardiac arrest survivors were aware of what was going on around them while they were 'dead' before being 'brought back to life', the study revealed.

Even more shockingly, there is some evidence to suggest that the deceased may even hear themselves being pronounced dead by doctors, The Mirror reports.

Dr Sam Parnia is studying consciousness after death and examining cardiac arrest cases in Europe and the US.

He said anecdotal evidence has found that people in the first phase of death may still experience some form of consciousness.

The expert told LiveScience that people who have survived cardiac arrest later accurately described what was happening around them after their hearts stopped beating.

He said: "They'll describe watching doctors and nurses working, they'll describe having awareness of full conversations, of visual things that were going on, that would otherwise not be known to them."

Explaining when a patient is officially declared dead, he said: "It's all based on the moment when the heart stops.

"Technically speaking, that's how you get the time of death."

His study is examining what happens to the brain after a person goes into cardiac arrest - and whether consciousness continues after death and for how long - to improve the quality of resuscitation and prevent brain injuries while restarting the heart.

Unlike the plot in Flatliners, however, when a person is resuscitated they don't return with a "magical enhancement" of their memories, said Dr Parnia.