Harry Mattson and Norma Wong, partners in a polling and consulting firm that was paid nearly $100,000 by the Harris campaign, arrived before 8 a.m. and remained in the grand jury chambers for several hours.

The panel is scheduled to call another witness, Lisa-Katharine Otsuka this afternoon. Otsuka is an associate of Mattson, and investigators have questioned whether money from the Harris campaign improperly went to Otsuka.

Harris and Otsuka say they do not know each other, and campaign officials say Otsuka had no formal role in the campaign and was not directly paid by it.

Otsuka appeared before the grand jury earlier this month but refused to testify unless she is granted immunity from prosecution.

She was indicted last month on an unrelated theft charge, and was arrested in August on suspicion of money laundering, promoting prostitution, and illegally operating a business.

Her attorney for the Harris grand jury matters, Victor Bakke, said he expected to discuss the parameters of an immunity agreement with prosecutors today, but did not expect Otsuka to testify today.

The investigation began earlier this year, after investigators from the State Campaign Spending Commission found what they believe is evidence that the Harris campaign deliberately hid the sources of some donations to evade campaign contribution limits.

Campaign officials insist the suspicion is baseless, and Harris' attorney says there is no connection between campaign contributions and the awarding of city contracts.

Employees from several companies that contributed heavily to the campaign and were awarded nonbid engineering and design contracts have also appeared before the grand jury.