Dutch food group Numico NV, faced with a crumbling share price, denied on Tuesday that its food supplement unit GNC deliberately sold expired products in the United States, Reuters reports.
"These allegations are totally unjust," a statement said.
Numico shares have shed 16 per cent in under two weeks, partly due to an investigation launched by the Florida Attorney General into a complaint that General Nutrition Companies (GNC) had sold expired vitamins to boost profits.
Numico, the world's biggest vitamin and food supplement maker, said GNC might have sold some old products, but this was not intentional.
"If some out-of-date product was encountered...such happened by accident and we highly regret this," the statement said.
The Wall Street Journal on Monday quoted former GNC officials as saying they were instructed to put expired merchandise back on shelves and try to sell them.
The former officials were quoted by the newspaper as saying that Tom Dowd, a former senior vice president of GNC, told executives in a conference call to try to sell out-of-date vitamins and food supplements if they were not rancid.
"We really don't know if he said something like that, but if he did so he was not speaking on behalf of the company," Numico spokeswoman Elvira Luykx said on Monday.
Numico said the allegations would have no impact on its results and reiterated its outlook for the full year that core sales and cash earnings would rise at least 15 per cent.
It had repeated the outlook on August 16 when it released half year results.
Food supplements account for around 60 per cent of Numico's turnover following the $2.5 billion takeover of GNC in 1999.
Shares in Numico lost more ground on Tuesday, slipping 1.37 percent to 38.28 euros by 0835 GMT, a fresh 17-month low.
So far this year, Numico shares have shed 29 per cent and underperformed the Dow Jones Stoxx food and beverage index by 26 per cent.