ap photo Cartons of eggs are on display at HarvesTime Foods on, Jan. 5 in Chicago. U.S. Sen. Jack Reed sent a letter Tuesday, Jan. 24, asking for the Federal Trade Commission to investigate whether egg prices have been improperly manipulated by producers.

OMAHA, Neb. — With egg prices more than doubling in the past year, calls are coming for an investigation into possible price gouging.

U.S. Sen. Jack Reed sent a letter Tuesday asking for the Federal Trade Commission to investigate whether egg prices have been improperly manipulated by producers. A farmer-led advocacy group called Farm Action made a similar request last week arguing that there “appears to be a collusive scheme among industry leaders to turn inflationary conditions and an avian flu outbreak into an opportunity to extract egregious profits.”

The spike in egg prices has been attributed to the millions of chickens that were slaughtered to limit the spread of bird flu and farmers having to compensate for inflation driving up their costs.

But even though roughly 43 million of the 58 million birds slaughtered over the past year to help control bird flu have been egg-laying chickens, the size of the total flock has only been down 5 percent to 6 percent at any one time from its normal size of about 320 million hens.

The national average retail price of a dozen eggs hit $4.25 in December, up from $1.79 a year earlier, according to the latest government data.

“At a time when food prices are high and many Americans are struggling to afford their groceries, we must examine the industry’s role in perpetuating high prices and hold those responsible accountable for their actions,” Reed, a Rhode Island Democrat, said in his letter to the FTC.