The multi-vitamin Centrum, which is produced by drug manufacturer Pfizer, was withdrawn from Irish shelves this week because the Irish public was not informed of a possible link to genetically modified ingredients contained in the product.

Centrum contains soybean oil, but the product packaging did not indicate it may have come from genetically modified soybeans from America.

Responding quickly, Pfizer said Centrum would not be on sale in the Irish market until the end of the month, while it addressed the problem. The drug manufacturer refused to indicate how many bottles of Centrum had been taken from Irish shop shelves, but it admitted the product should have been more clearly labelled.

A spokesperson told the press this week: "At the beginning of September, Pfizer began a voluntary withdrawal of Centrum food supplements from retail shelves in the European region.

"In Ireland, the majority of supplements were off the shelf within a 72-hour period and have not been available for sale here for over three weeks."

"The material in the formulations was originally qualified as a non-genetically modified organism (GMO) ingredient. However, we learned that the soybean oil may be derived from genetically modified soybeans grown in the United States."

Pfizer insisted that the product was withdrawn because of a labeling issue and not a safety issue.

"As a result of this use of GMO soybean oil, the finished products should have a GMO statement on the label," the spokesperson said.

In response to the controversy Pfizer said it was currently manufacturing completely GMO-free Centrum.

"We anticipate product shipments will resume towards the end of October," the spokesperson added. "We would repeat that there is no safety issue with the Centrum range of products. This voluntary action ensures consumers can't access incorrectly labelled product."