"Just over a year ago, gold researchers Nick Laird, Bron Suchecki, Koos Jansen and myself took a shot at estimating how much physical gold was accounted for in London within the gold-backed ETFs and under Bank of England custody. The results of that exercise are highlighted in September 2015 articles “How many Good Delivery gold bars are in all the London Vaults?….including the Bank of England vaults”, and “Central Bank Gold at the Bank of England”, and also on Nick Laird’s website in a post titled “The London Float” which contains some very impressive charts that visualize the data. Some of the latest updated versions of these charts from www.goldchartsrus.com are featured below.
Given that its now just over a year since that last set of calculations, it made sense at this point to update the data so as to grasp how many Good Delivery golds bars held in London is spoken for in terms of ownership, versus how much may be unaccounted for. Estimating gold held in London vaults is by definition a tricky exercise, since it must rely on whatever data and statements are made available in what is a notoriously secret market, and there will usually be timing mismatches between the various data points. However, using a combination of published sources from the Bank of England, the London Bullion Market Association (LBMA), the Exchange Traded Fund websites, and UK gold import/export data, it is possible to produce some factual numbers."
Read the entire update by Ronan Manly here.
You should also have a look at The London Gold Float.