Border guards seized 160 kilograms of dried khat, an illegal plant traditionally cultivated in Africa and the Arabian Pennisula, said the Canadian Border Services Agency Friday.

When chewed, the plant is known to have mildly stimulating effects.

Khat is banned in Canada, the United States and in many European countries.

A release by the Canada Border Services Agency stated that it received an air cargo shipment of 20 boxes on two wooden pallets from the United Kingdom on Aug. 20, which was declared as "green tea."

Each box contained four sealed plastic bags. Officers opened them and found a loose and green leafy plant material, which later tested positive as khat. The shipment has been turned over to the RCMP for a further investigation.

The CBSA said this is its largest khat seizure so far this year and the 24th in Alberta.

In January 2012, a Fort McMurray man returning from England was arrested in Calgary on after 30 kilograms of khat were allegedly found in his checked baggage.

Then in May 2012, 50 kilograms of khat was discovered at the Edmonton International Airport in the checked bags of two British nationals travelling together.