Efforts by coal giant Xstrata to purge a parody mining commercial from video site YouTube have backfired, re-igniting interest in the months-old clip.

The commercial, created as part of a union campaign by former Chaser member Charles Firth, was deleted from the Australian Manufacturing Workers Union's YouTube account in early December after a complaint from Xstrata.

However, a different YouTube user re-uploaded the video to YouTube last week.

The ad uses footage cribbed from a mining industry advertisement but replaces the soundtrack with a voice-over of an "environmental manager" talking about how mining uses large amounts of water.

Media site Mumbrella published a story about the ad at lunchtime on Friday but removed the embedded video later that afternoon after receiving legal threats from Xstrata.