Here is a story I posted in an earlier discussion (last year) about similar things.
Of course, not all bodies that end up down a shaft got there accidentally. This case is interesting, as in spite of all the trouble the murderers went to hide the body and make it unidentifiable, they left the victim's wallet in his back pocket!
"In June 1988 two timber cutters exploring a mine shaft in country Victoria discovered a badly decomposed, headless body. Documents on the body established that it was that of Phil_H. (age 35, unemployed), better known to his friends as Rhino. The story the police were able to piece together indicated that for some time Rhino had been a source of trouble for his friends.
On the day he was killed. Rhino had engaged in a heated argument with Perry H. (age 20, unemployed). Partly the argument was because Rhino had earlier broken into the house of Perry's sister, stealing a video and stereo. Also, Perry was certain that Rhino had stolen some pills from one of the rooms in his house. In response, Rhino was said to have threatened not only Perry, but Perry's children, and was seen to have struck one of the children.
The group (several lived at the house) then calmed down a bit, and settled into some serious drinking. After a few hours, most had gone to sleep. One of the residents of the house stated that Perry then came up to him and said: Let's kill the scumbag. The two then finished off about half a bottle of whisky, and by then were in an aggro mood. The two went out to Rhino's truck, where Rhino slept. Perry went in through the passenger's door, his friend went on the driver's side. The friend stated that at this point Perry said something like, how you gain? and Rhino turned to the friend and said: 'G'day'. The friend states that at this point he told Perry to forget about it, but that as he was turning away he heard a couple of thumps and then heard Rhino gurgle. The friend returned to the truck, and looking at Rhino told Perry that he was dead, but Perry still stabbed Rhino two or three more times in the chest.
The conspirators first disposed of the body burying it in a shallow grave in nearby bushland. Becoming apprehensive that it would be discovered, they returned later to dig the body up and then dispose of it down the mine shaft. At some later point one of the co-defendants returned to the scene and cut the head off the body and buried it in isolated bushland some distance away. When questioned later, Perry said that: I wouldn't have done it if he didn't threaten the people I love. (Case No. 2329-88)"
This story is from Ken Polk's book When Men Kill, Scenarios of Masculine Violence.