A massive haul of more than 32,000 stolen kegs and casks have been seized in a series of raids across the Midlands.
Kegs and casks with a replacement value exceeding £2.5m were recovered and 17 arrests made.
Keg Watch - a trade association that tracks and recovers stolen containers - and Staffordshire and West Midlands Police carried out the raids earlier this month.
David Hopwood, chairman of Keg Watch and head of security for Coors said: "This is absolutely massive, it will have a major impact no doubt on the losses that the brewers have been suffering. It's certainly the largest operation or recovery of its kind over the last 25 years."
Almost all of the kegs and casks recovered were damaged beyond repair.
The containers are attractive to thieves for their scrap metal value, which has increased significantly over the past four years due to the rising price of stainless steel.
"We are not going to sit back now on our laurels, we need to pursue these people and continue to work hard to identify who is supplying this illegal market in the first place," he added.
Stolen kegs cost brewers millions every year. Since April 2007 over 105,307 kegs and casks have been recovered in raids.
Julian Grocock, chief executive of the Society of Independent Brewers (SIBA) said: "It's a big concern. Whilst of course the major costs are borne by the larger breweries, with their huge numbers of containers, for the micro brewer who might only have a small number of casks the loss of just one can be a significant hardship."
Keg Watch and the police are now working with the brewers to establish where the containers came from and who was supplying them.