A poultry farmers association in Kyoto Prefecture falsely labeled and sold some 50,000 eggs six months after they were produced, health officials said Sunday.

The officials said the public health center in Uji recently checked eggs shipped to retailers by the association in Joyo following complaints from consumers about a strange taste.

It found the eggs were produced in mid-July but marketed in early December with labels falsifying the dates of production.

According to the health officials, the association had an oversupply of eggs in June so it kept unsold eggs in refrigeration, then decided to sell them to avoid the cost of keeping or disposing of them.

A manager decided the eggs were "no problem" after testing their quality Dec. 1 and allowed them to be shipped to some 12 retailers in Osaka and Kyoto, the officials said.

Twenty-seven consumers who ate the eggs complained about food poisoning symptoms, but no evidence was found that the eggs were the cause of the sickness.

The food hygiene law does not require farmers to include production dates on labels for eggs, but the center asked the association to prevent any recurrence of the situation.

The association fired the manager as of Jan. 1.

"We are sorry we have failed to live up to consumers' trust," association official Satoshi Nishino said. "We will strengthen quality checks and do our utmost to avoid a recurrence."