Customs officers have uncovered a huge illegal bottling plant in Cardiff, capable of producing thousands of litres of counterfeit vodka.
Customs officers said about £500,000 of duty had been avoided
The factory, on the Curran Embankment, Grangetown, was uncovered by HM Revenue and Customs on Thursday.
Officials warned people who have bought "Christoff Vodka" to pour it away, as it may contain methylated spirits.
Three Polish men arrested in connection with the find have been released without charge.
The factory was being dismantled by customs officers.
Kathryn Corcoran, from HM Customs said it was a "big operation".
"It's certainly the largest seizure of illicit alcohol we've had for quite some time in the Cardiff area," she said.
The bottling plant has been dismantled by custom officers
"We're very concerned because we don't know exactly what this supposed vodka contains.
"We're very keen to work with the council and get this message out that if people have this vodka they should perhaps pour it down the drain because we cannot guarantee it's what they've think they have bought."
Ms Corcoran said 5,000 bottles had been found "labelled and ready to go" and vats containing thousands more litres which were waiting to be bottled, equating to about £500,000 in lost revenue altogether.
Officers also found methylated spirits and industrial alcohol in the warehouse.