British Transport Police have found 260 canisters of laughing gas in Canterbury.
They made the discovery of nitrous oxide while attending Canterbury East train station earlier this week.
Nitrous oxide is an anaesthetic gas used for pain relief during dentistry and childbirth, but in the last few years it has become popular with clubbers as a way of getting high.
The BTP said: “Officers attended Canterbury East railway station and seized a quantity of nitrous oxide canisters scattered across the car park.
“Inquiries are ongoing to identify any suspects.”