AT times TV has the ability to genuinely shock.

Sometimes it's because the programmes on offer are just so woeful. But at others, it's because of the nature of the topics covered.

Last night on Channel Four, Reverend Death was a documentary following the work of an American minister, George Exoo.

On the face of it Rev George looked like any other midwestern minister. With his wire rimmed glasses and cheery smile he looked like any other pastor tending his flock.

But as Jon Ronson's disturbing documentary revealed George has a mission in life - to help people commit suicide.

As a self-confessed midwife to the dying' the Rev George and his assistant Susan claim to have helped over 100 people end their lives - and not just those who were terminally ill.

It was rather like watching something Louis Theroux might investigate with a darker twist.

One reason why the doumentary was so disturbing was that film-maker Ronson did not attmpt to impose any form of editorial comment on matters, he just let Rev George talk to the camera and followed him around as he did his daily routine.

This contrast between the ordinary and the extradorinary made watching it even more chilling.

It was one of those programmes you come away from almost doubting what you have witnessed.