LOCAL ELECTIONS / L.A. MAYOR : City Will Probe Cash Gifts to Woo Campaign : Inquiry: The candidate is returning nearly $6,000 given in apparent violation of law.

Mayoral candidate Michael Woo’s campaign has received nearly $6,000 in cash contributions in apparent violation of city election laws, according to records and interviews.

After inquiries by The Times on Wednesday, Woo campaign officials moved hastily to return the questionable contributions, and the city Ethics Commission said it plans to conduct an investigation.

Despite written and oral warnings from Ethics Commission officials in recent months, Woo’s campaign has accepted about 20 cash donations ranging from $40 to $1,000 from supporters at a series of fund-raisers, Woo campaign officials acknowledged.

There is a $25 limit on cash contributions in City Hall elections, in part because cash donations are nearly impossible for government auditors to track. Violations of the limit can lead to fines of up to $5,000 per incident, Ethics Commission officials said.

Garry South, Woo’s campaign communications director, said the violations were inadvertent. They were caused by “a staff member . . . who did not understand it was not legal to take cash from donors,” he said.

The aide, David Lang, is a longtime member of Woo’s City Council staff who has taken a leave to work on the campaign. Lang could not be reached for comment.

The commission’s investigation and the hurried return of the funds are embarrassing for Woo, the race’s early front-runner. He has often cited his authorship of the city’s tough new election and ethics laws.

The probe comes amid criticism by rivals that Woo made extensive use of a special political account to build computer files and underwrite travel that helped jump-start his mayoral bid. Woo denies any impropriety, and the Ethics Commission is auditing the account.

Most of the cash contributions in question appear to have come from Asian-Americans, both in Southern California and from as far away as San Jose and Chicago. Woo, who would be the city’s first Asian-American mayor, has tapped a huge nationwide network of Asian-American professionals and small-business owners for donations totaling 30% to 35% of the $1 million he has raised, according to records and interviews.

The cash contributions were deposited in Woo’s campaign account after they were converted to cashier’s checks at a Chinatown bank with long, close ties to Woo’s family. Woo’s father, Wilbur Woo, helped found Cathay Bank, and Woo holds stock in the institution.

Records and interviews show that bank officials have donated several thousand dollars to Woo’s campaign and have helped it obtain information on donors.

South said he could not comment “with any specificity” on how extensively involved the bank’s officials have been in Woo’s fund-raising efforts. He said the bank was used to obtain cashier’s checks because it is one of the closest to Woo’s Chinatown campaign headquarters.

The apparent violations surfaced when The Times questioned those listed as donors of the cashier’s checks--many of which were sequentially numbered and apparently purchased in blocks.

Four donors said they did not purchase the cashier’s checks, and others declined to provide details of how the donations were made. Chuck Park, who runs a Los Angeles communications firm, said he made a $150 cash donation at a Korean-American event for Woo. Joe Campbell, a general contractor who works in Little Tokyo, said he dropped by a Woo fund-raiser in Chinatown and made a $100 cash donation.

Myung K. Cho, president of Comack Trading Inc. in Los Angeles, was listed as having made made a $1,000 donation with a Cathay Bank cashier’s check. He said he made the donation through a friend who “told me we have to help. I didn’t do it straight (to the Woo campaign).” He declined to provide further details.

Others listed as giving with the cashier’s checks live in such cities as Torrance, Alhambra, Oxnard, San Jose, Stockton and Chicago.

South said all of the Cathay Bank cashier’s checks appear to have been improper cash donations. But he said they represent a small part of the total funds raised by Woo.

Rebecca Avila, the Ethics Commission’s deputy executive director, said the agency’s enforcement division will investigate the circumstances surrounding the donations. “Ignorance is not an excuse” in such cases, she said. The issue was addressed during mandatory election workshops conducted for all candidates and their campaign treasurers, she noted.

“I think it was like the third thing I said,” Avila recalled. “I said: ‘There are no anonymous contributions over $200, and no cash over $25.’ ”