London, Sept 1 - All U.S. long grain rice shipments into Britain will be tested for an unauthorised strain of genetically modified (GMO) rice, the UK Food Standards Agency said on Friday.
"The Agency is taking this action to ensure that future supplies of rice are GM free," the FSA said in a statement.
"All imports of rice are being held at ports until they can be certified free of GM."
Last week the EU tightened requirements on U.S. long-grain rice imports to prove the absence of a GMO strain known as LL Rice 601 marketed by Germany's Bayer AG and produced in the United States.
The EU decision followed the discovery by U.S. authorities of trace amounts of LL Rice 601, engineered to resist a herbicide, in long-grain samples that were targeted for commercial use -- the first time this had happened.
On Thursday the European Commission said a shipment suspected of containing the unauthorised rice arrived in the Netherlands on Saturday but had not entered the market.
The shipment in Rotterdam was partly destined for Britain and partly for Germany.