KABUL: Afghan President Hamid Karzai's top challenger in disputed elections alleged Tuesday the embattled head of state engineered the resignation of a chief fraud investigator to cast doubt over a process that may force a runoff vote.

Results from the August 20 elections have been delayed by more than a month because of massive fraud allegations. A five-member, UN-backed panel is investigating the charges, and its decision on how many votes to throw out will determine whether Karzai wins outright?- as preliminary results show?- or if a runoff is required.

One of the two Afghans on the Electoral Complaints Commission, Maulavi Mustafa Barakzai, resigned Monday because, he said, the three foreigners on the panel?- one American, one Canadian and one Dutch?- were "making all decisions on their own."

"Barakzai's resignation has direct connection to Karzai. It was Karzai's idea," Saleh Mohammad Registani said. "Karzai is trying to bring the work of the ECC into question."

He said Barakzai was widely considered to be biased toward Karzai.

Representatives for Karzai could not immediately be reached for comment.

Barakzai was appointed by the Afghan Supreme Court, whose judges were named to their posts by the president.

Barakzai has held a number of government posts, but none overtly political. He has served as the head of the Supreme Court's Islamic verdict department and its documentation department. During 2005 elections, he headed the Media Complaint Commission, overseeing coverage of the election.

The operating procedures of the panel allow it to continue working and even issuing decisions with fewer than five members. The group needs only a quorum of three people?- one of them Afghan?- to meet and issue rulings.

Registani argued that even the appearance of an injustice could be used to undermine the credibility of the commission.

"If anything comes out of this that is against Karzai's interests, then Karzai will say the Supreme Court member was not present at the last crucial meetings, so all these decisions were made by foreigners," Registani said.

Abdullah's camp says its is confident the election will go to a second round.

Abdul Malik Kamawi, a Supreme Court justice, said the court was ready to appoint another commissioner, but only if Barakzai submitted an official resignation.

The Electoral Complaints Commission has not yet received a formal resignation from Barakzai, said Nellika Little, a spokeswoman for the group.