(AFP) - Belgium accused the Netherlands on Wednesday of failing to inform it that eggs were tainted with insecticide despite knowing about the problem since last November, as Europe's latest food safety scandal deepened.

Newly appointed Agriculture Minister Denis Ducarme told a parliamentary hearing that Belgian's food safety agency obtained an internal Dutch document that "reports the observation of the presence of fipronil in Dutch eggs at the end of November 2016."

"When a country like the Netherlands, one of the world's biggest exporters of eggs, does not pass on this kind of information, that is a real problem," said Ducarme, adding he has demanded an explanation from his Dutch colleagues.

There was no immediate response from the Dutch government.

The European Commission, which oversees the 28-nation European Union's food safety alert system, refused to comment on if and when it was told about the reported Dutch finding.

"The hearing is still ongoing, so we will not have a running commentary on everything that is being said or presented at that meeting," spokesman Daniel Rosario told reporters.

The Belgian hearing was called in response to an admission by officials at the weekend that they too knew about fipronil in eggs back in June, but kept it secret for nearly two months because of a parallel criminal fraud investigation.

The insecticide scandal only became public on August 1 when authorities in the Netherlands ordered eggs pulled from supermarket shelves and urged shoppers to throw theirs away.

Contaminated eggs have since been discovered in Germany, Belgium, Sweden, Switzerland, Britain and France, with several supermarkets pulling millions of eggs off the shelves.

Fipronil is commonly used in veterinary products to get rid of fleas, lice and ticks but it is banned by the EU from being used to treat animals destined for human consumption, such as chickens.

In large quantities, the insecticide is considered by the World Health Organisation to be "moderately hazardous" and can have dangerous effects on people's kidneys, liver and thyroid glands.

The scandal has led to finger-pointing between Belgium, Germany and the Netherlands as they try to get to the bottom of how the scandal was able to happen.

Ducarme said that the Dutch knowing about the problem since November only emerged when the Belgian food safety agency "through certain contacts was transferred, by chance, internal information" from its Dutch counterpart.

If the Netherlands had notified Belgium sooner "our vigilance about fipronil would have been increased, greatly increased."

Germany has meanwhile demanded answers from both countries.

Criminal probes for suspected fraud are under way in Belgium and the Netherlands over the tainted eggs, but prosecutors in both countries have refused to give any details.

"The defrauders must be punished harshly by the courts because in order to enrich themselves personally, they have not hesitated to risk the health of consumers," Ducarme said.

The problem is believed to stem from a substance used by a Dutch company, Chickfriend, that farmers in the Netherlands and Belgium say they hired to treat their chickens.

A lawyer for a Belgian company, Poultry-Vision, says the firm sold it to Chickfriend but has not said where it got the substance.

The French government says a Belgian company -- which it did not identify -- mixed fipronil with another, lawful, substance.