Comptroller Alan Hevesi, who acknowledged last week that he owed the state more than $80,000 for using an employee to chauffeur his ailing wife, keeps in his home a state-issued computer that his campaign opponent alleges is primarily for his wife.

A spokesman for Mr. Hevesi, David Neustadt, said it is not inappropriate that “the head of a large organization that’s totally computerized would have a computer in his home.”

Mr. Neustadt said Mr. Hevesi’s wife does not use the computer because she no longer lives in the comptroller’s main residence in Queens but stays in the couple’s “small cottage” in Westchester.

Asked if Mr. Hevesi uses the computer for work purposes, the spokesman said, “I don’t know what he does when he gets on the computer.” He said the computer is the only one issued by the office to the comptroller and that Mr. Hevesi has no plans to return it.

Mr. Hevesi’s opponent, J. Christopher Callaghan, a former treasurer of Saratoga County who said he learned of the computer from a confidential source inside the comptroller’s office, said it was another example of Mr. Hevesi accepting an improper perquisite.

Last week, Mr. Hevesi said he would repay the state $82,688, the amount he estimated that he owed taxpayers for having one of his employees serve as a chauffeur for his wife for more than three years.

His approval rating has fallen to 37%, an eight-point drop since June and the lowest point in his four-year tenure, according to a Quinnipiac University poll released yesterday. The poll shows him leading Mr. Callaghan, who is not known to most registered voters, 59% to 21%.