VANCOUVER - Mounties in BC suspect the seizure of $1.5-million of cocaine last week is linked to international drug trade after the narcotics were spotted being dropped into a ditch just north of the US border.

RCMP Cpl. Holly Marks said traffickers typically drop off large amounts of drugs "for somebody else to pick it up," adding it's a tactic often used in the cross-border drug trade.

A total of 21 kgs of cocaine were seized in two hockey bags on Oct. 4 in south Langley. Police haven't said whether the drugs were being imported or exported.

Mounties are still looking for a third bag, based on an anonymous witness report that suggested a van with three people inside made the drop, that included an extra, unfound bag.

"It's more than likely it's having to do with the border crossing," Marks said. "We have it happen quite a bit at the border."

She said the most recent seizure highlights a possible increase in cross-border drug trade. Last month, 20 kilograms of MDMA, a typical ingredient in ecstasy pills, were seized when police arrested a man hiding in a ditch near the border.

A man from Mexico was charged with trafficking in that seizure. The wrapped bags of MDMA were worth more than $1 million.