Aug. 22 (Bloomberg) -- The Scottish government’s decision to release Lockerbie bomber Abdel Basset Ali al-Megrahi makes a “mockery of the rule of law” and gives comfort to terrorists around the world, FBI Director Robert Mueller said.

“I am outraged at your decision,” Mueller said in a letter to Scotland’s Justice Secretary Kenny MacAskill dated Aug. 21 and posted on the FBI’s Web site. “Your action rewards a terrorist even though he never admitted to his role in this act of mass murder.”

Al-Megrahi, who is dying of prostate cancer, was released from prison Aug. 20 by MacAskill. He was sentenced in 2001 to serve 27 years for the 1988 killing of 270 people in the bombing of Pan Am Flight 103 over the Scottish town of Lockerbie. Doctors estimated earlier this month he had less than three months to live.

When he arrived at Tripoli’s airport, al-Megrahi, 57, was greeted by hundreds of Libyans who cheered and waved Scottish flags. President Barack Obama called the display “highly objectionable.”

MacAskill said Aug. 20 he was “conscious that there are deeply held feelings, and that many will disagree with whatever my decision.” While MacAskill rejected a request by Libya to transfer al-Megrahi to a prison in the North African country, the decision to release him due to illness defied calls from the U.S. government and many American relatives of the bombings victims.

“You have given the family members of those who died continued grief and frustration,” Mueller wrote. “You have given those who sought to assure that the persons responsible would be held accountable the back of your hand.”

Single Sneaker

MacAskill couldn’t have spent much time with the victims’ families and “could not have visited the small wooden warehouse where the personal items of those who perished were gathered for identification -- the single sneaker belonging to a teenager; the Syracuse sweatshirt never again to be worn by a college student returning home for the holidays; the toys in a suitcase of a businessman looking forward to spending Christmas with his wife and children,” Mueller wrote.

Mueller’s letter noted that he was the assistant attorney general in charge of the investigation and indictment of al- Megrahi in 1991, saying that “although the FBI and Scottish police, and prosecutors in both countries, worked exceptionally closely to hold those responsible accountable, you never once sought our opinion.”

Al-Megrahi, a former Libyan intelligence officer, has maintained his innocence in the bombing of the Boeing 747 flying to New York from London on Dec. 21, 1988. He was the only person convicted in the atrocity.

Qaddafi’s Hug

Libyan leader Muammar Qaddafi, who has ruled Libya since seizing power in a 1969 coup, hugged al-Megrahi after his return and praised Scottish authorities for releasing him, the Associated Press reported. Qaddafi’s government has sponsored rebel movements in countries including Sudan, Chad and Niger, and accepted responsibility for the Lockerbie bombing.

Qaddafi abandoned a nuclear-arms program and renounced terrorism between 2002 and 2005. Qaddafi last year met former U.S. Secretary of State Condoleezza Rice in what was the highest-level official U.S. visit to Libya in more than 50 years.

Relations between the U.S. and Libya reached a low point with the 1986 attack on Tripoli and Benghazi ordered by former U.S. President Ronald Reagan, who had described Qaddafi as a “mad dog.”

To contact the reporter on this story: Joshua Gallu in Washington at jgallu@bloomberg.net.

Last Updated: August 22, 2009 13:20 EDT