Top officials in President Hamid Karzai’s government have repeatedly derailed corruption investigations of politically connected Afghans, according to U.S. officials who have provided Afghanistan’s authorities with wiretapping technology and other assistance in efforts to crack down on endemic graft.
In recent months, the U.S. officials said, Afghan prosecutors and investigators have been ordered to cross names off case files, prevent senior officials from being placed under arrest and disregard evidence against executives of a major financial firm suspected of helping the nation’s elite move millions of dollars overseas.
As a result, U.S. advisers sent to Kabul by the Justice Department, the FBI and the Drug Enforcement Administration have come to see Afghanistan’s corruption problem in increasingly stark terms.
“Above a certain level, people are being very well protected,” said a senior U.S. official involved in the investigations.
Karzai spokesman Waheed Omar denied investigations had been derailed.
“There is no case, no instance, in which the palace or anyone from the palace has interfered with a case,” he said.
Afghanistan is awash in international aid and regarded as one of the most corrupt countries in the world. Even as the U.S. and its allies pour money in, U.S. officials estimate that as much as $1 billion a year is flowing out in a massive cash exodus.
For the Obama administration, the ability of Afghan investigators to crack down on corruption is crucial. If American voters see Karzai’s government as hopelessly corrupt, public support for the war could plunge.
Meanwhile Sunday, the NATO-led command stressed that military operations to secure vast areas of Afghanistan would not be delayed by the ouster of its top commander.
To reinforce the message, NATO announced that more than 600 Afghan and international troops were battling al- Qaeda and Taliban forces Sunday in the Kunar province.
NATO and U.S. forces are awaiting the arrival of Gen. David Petraeus, who is taking over as commander from Gen. Stanley McChrystal.
NATO deaths also are climbing daily. A U.S. service member was killed in a bomb attack in the south, along with two others in the fighting in Kunar. NATO also reported that a service member from the international coalition was killed Sunday during an insurgent attack in the south and four others died in a roadside bombing in the north.
The Associated Press contributed to this report.



