The increase came after one batch of Vietnamese shrimp contained harmful substances/drugs (etoksihina).
A ban on shrimp exports from Viet Nam may be decided if other prohibited substances are identified.
In the past, the same approach was applied after the detection of the harmful substance triftoralina was found in Vietamese shrimp. In that case, Japan increased the frequency of its inspections from 30 per cent to 100 per cent.
