China customs has suspended the clearance of canola imports from Canadian company Richardson International Limited and relevant firms after harmful pests were discovered in their imports.

The suspension of clearance involves their canola imports shipped from March 1, according to a warning notice issued Thursday by the General Administration of Customs (GAC).

The warning will be valid until further notice, GAC officials said.

The move is taken to protect China's agriculture production and ecological safety, the GAC said.

Local custom offices of Huangpu, Dalian, Nanning and Shenzhen had recently detected harmful pests including Pseudomonas syringae, the GAC said and suggested that they strengthen quarantine on Canadian canola imports and report the results to the GAC.

The GAC will evaluate the results, timely adjust warning measures and inform local canola import firms.

The GAC said it had canceled Richardson's and other relevant firms' registration to ship canola to China and briefed the Canadian Food Inspection Agency about the situation.