The Georgia Aquarium told a judge on Friday that federal regulators manipulated data and ignored facts when they refused to allow the import of 18 beluga whales from Russia.

“Your honor, if you listen carefully they are bobbing and weaving,” the aquarium’s Washington D.C.-based lawyer George Mannina said in U.S. District Court in Atlanta. He accused federal officials of “cooking the books,” alleging they engineered data to harm the aquarium’s application.

The Atlanta attraction wants to bring the whales to the United States. Their permit application is the first in more than two decades seeking to import marine mammals captured in the wild. The National Oceanic and Atmospheric Administration (NOAA) Fisheries in 2013 denied the permit saying approving the application could open the door to widespread hunting and collection of belugas and other mammals.

Friday’s hearing in Atlanta waded into highly-technical scientific studies and statistics. Lawyers for the aquarium and NOAA sparred over whether data showed that the removal of the belugas from their original home in the Sea of Okhotsk, off the northwest coast of Russia, would have a negative impact on the population there.

Mannina said the aquarium had made use of a formula commonly used by federal marine officials, only to then have it rejected.

But a federal lawyer said Friday that formula was only part of the equation and that regulators rested their ultimate decision on many different pieces of information.

“The agency did draw a reasonable and rational conclusion based on the set of evidence,” Department of Justice lawyer Clifford Stevens said.

“It is ill-advised to rest everything on a formula.”

U.S. District Court Judge Amy Totenberg peppered the lawyers with questions and, at one point, mused that she was troubled by the “extremity of data poverty” for the belugas, who live in remote Arctic and sub-Arctic waters.

Totenberg is expected to issue a ruling on the coming months,.

Collected from 2006-2011, the 18 Beluga whales are currently being held at a marine research center along the Black Sea.

The 1972 Marine Mammal Protection Act bans the collection and import of mammals to the United States but it makes an exception for public display.

If the whales are imported, they would be put on display in aquariums in Atlanta and Chicago as well as Sea World parks in Florida, Texas and California.

The Georgia Aquarium currently has three belugas on display. One of them has given birth to two calves at the aquarium but both have died.