The Enquirer has been sent a recording of the live CCTV footage showing the accident last month on a platform at the London tube station.
A winch was being used to pull a cable through a platform invert and a worker had a rope tied around his waist with the other end being fed through the winch.
The winch snagged and lifted from its mounting moving forward five metres pulling the worker with it.
His safety helmet was knocked off before he fell headfirst into a manhole.
The victim suffered deep cuts to his head and shoulder and back injuries which were treated in hospital.
The London Underground Renewals and Enhancements Stations (SWIP) were main contractor on the site.
It is understood similar works have been suspended while a safety investigation takes place.