Afghan President Hamid Karzai has vowed to fight corruption in his country following an election marred by widespread voter fraud. (Musadeq Sadeq/Associated Press)

The Afghanistan government's resolve in fighting graft and bribery is being tested this week in the case of the mayor of Kabul, who on Monday was sentenced to four years in jail for corruption but continues to run the country's capital city.

Mayor Abdul Ahad Sahebi was found guilty on Monday of awarding a contract without opening it up to competition. He was sentenced to four years in jail and ordered to repay $16,000 allegedly lost as a result.

The 63-year-old Sahebi remains free pending his appeal to a higher court. Afghan attorney general's office investigator Hafizullah Hafiz said Sahebi wrote a letter pleading with officials not to incarcerate him because of health concerns.

But law enforcement officials remain concerned that Sahebi continues to run the city, even after the conviction.

"From the eyes of the attorney general, he is not mayor of Kabul," said Enyatullah Kamal, judicial investigation chief in the Afghan attorney general's office.

"It was a surprise that he has gone back to his job — that he dared to give a press conference. The court is the court in this country and nobody can stop the decision of the court. The court made a decision."

Sahebi maintains his innocence, however, and has asked the government of Afghan President Hamid Karzai, parliament, the attorney general's office and the Supreme Court to investigate what he says is a plot to remove him from office.

"I am mayor. I am continuing my job," he said Wednesday. "I don't accept the court's decision. There is a conspiracy against me."

Mohammad Yaseen Usmani, the top official in the Afghan government's High Office of Oversight and Anti-corruption, said the mayor's release on Monday did not violate any law.

But the case suggests enforcement of existing laws may be the most difficult challenge for Afghan President Hamid Karzai, who has vowed to root out corruption at all levels of government.

"The decisive element in order to fight corruption in Afghanistan is not the constant discussion of new mechanisms and new structures and new commissions," said Norwegian Kai Eide, the top UN official in Afghanistan.

"We may need that. But structures do exist. A legal system does exist that is able, to a large extent, to address corruption."

2nd-most corrupt country in world

Afghanistan receives billions of dollars a year in international aid since the fall of the Taliban and the establishment of Karzai's first government. But it was recently named by international watchdog group Transparency International the second-most corrupt country in the world, ranking behind only Somalia.

Corruption is a concern for countries like Canada, the United States and Britain that are aiding the Afghan state in fighting the Taliban and al-Qaeda insurgents militants that control much of country, since it undermines the legitimacy of the government in the eyes of the Afghan people.

Aware of the concerns of the international community, Karzai vowed to root out corruption after retaining his presidency in August's election, which was marred by widespread fraud during the first round of voting.

"We will do our best through all possible means to eliminate this dark stain from our clothes," he said in a speech in November.

His main opponent in the election, former foreign minister Abdullah Abdullah, dropped out of the race in the second round over concerns that the Afghan election commission could not be trusted to run a fair and free vote.

Karzai is expected to name the members of his next cabinet in the coming days, a process that will be closely watched by the United Nations and international observers, many of whom have warned the government that continued support in the war against the Taliban is dependent on fighting corruption.

With files from The Associated Press