PORTLAND — A big game hunting guide from Gray was fined more than $18,000 in U.S. District Court Friday for illegaly transporting four cougars and six black bear gall bladders from Washington state to Maine.

Daniel A. Liberty, 47, was found guilty on three criminal charges of violating the Lacey Act of 1981, which prohibits the interstate transportation and sale of illegally taken fish and wildlife.

Liberty was one of 25 people involved in a black market that illegally transported, sold, and distributed pelts and animal body parts around the world, according to Dick Stott, a special agent for the U.S. Fish and Wildlife Department.

Federal and state wildlife officials in Washinton state, Massachusetts, Connecticut, New York, Florida and Maine uncovered the illegal animal trade and Liberty pleaded guilty in April to the three counts.

The government had charged that on two separate occasions in 1988, Liberty had sold illegally taken cougar hides and black bear gall bladders to undercover wildlife officers.

The gall bladders from black bear and deer are valuable because they are used as aphrodisiacs or for medicinal purposes in countries in the Far East, Stott said.

The government alleged that the animals were untagged or hunted without permit as required by Washington regulations, therefore, Liberty may face further charges in that state.

Stott said the three-year undercover investigation, known as Operation Berkshire, traced the poaching of deer, bears and cougars throughout New England, New York, Washington, and Florida. He said the sting operation was a cooperative effort between federal agents and state wildlife officers.

U.S. Magistrate David M. Cohen sentenced Liberty to pay a $6,000 fine, or $2,000 for each violation, plus $8,825 to cover the cost of the federal investigation, $75 to a crime victims’ fund, and the cost of probation, or $3,480.

In addition, Liberty cannot hunt or guide hunters in the U.S. for the three years of his probation, Cohen said.

In January of this year, another Maine hunting guide, Philip B. Copp, 58, of Brunswick, was fined $10,000 in U.S. District Court, in Massachusetts, for illegally selling gall bladders in that state. In April, Copp was fined $6,000 in Florida State Court for selling gall bladders in that state, as well.