Grand jury transcripts released Wednesday in the illegal campaigning indictment of former Santa Clara County Supervisor George Shirakawa, Jr. raised new questions about the role of San Jose City Councilman Xavier Campos and his sister, Assemblywoman Nora Campos.

Shirakawa is charged with helping Campos, his friend and former aide, win the San Jose City Council seat vacated by his sister in 2010 by sending out campaign postcards falsely impersonating Xavier Campos' opponent and suggesting she was a communist. Xavier Campos has denied any involvement with the mailers and has not faced any charges while Nora Campos, D-San Jose, has for the most part stayed out of the saga's public spotlight.

But criminal grand jury transcripts of the Shirakawa case made public Wednesday showed prosecutors asking pointed questions to both Campos siblings, who were subpoenaed to testify before the jury in a closed-door hearing on Oct. 23.

Upon taking the stand, Xavier Campos spelled his name and then repeatedly invoked his Fifth Amendment right to avoid making statements that could incriminate himself. Even when prosecutors asked him basic questions -- such as his job title and whether he was the brother of Nora Campos -- Campos refused to acknowledge them, saying only that his lawyer had advised him not to comment.

During the hearing, Xavier Campos' attorney spent several minutes trying to persuade Santa Clara County Superior Court Judge Peter Kirwan to let Campos leave the stand so prosecutors could not ask him more questions. The attorney, Gregory Ward, said it would only make Campos "look bad" to repeatedly plead the fifth.

When that failed, Ward asked for prosecutors to read jurors a statement that would make it clear that pleading the fifth was not necessarily an indication of any wrongdoing.

At one point, an unidentified juror asked: "We would like to know why we are not trying to indict Xavier. Is there not enough evidence?"

Another juror interrupted, saying: "You can't ask that," and the proceedings continued.

Through their spokespeople, both Camposes declined to comment. A spokesman for Nora Campos said the transcripts speak for themsleves.

Throughout the closed-door hearing, the Santa Clara County District Attorney's Office tried to link Shirakawa and the Campos siblings.

They noted the trio shared many of the same campaign staff and helped each other run for office. Of particular concern to prosecutors was that Nora Campos had given Shirakawa a $5,000 donation from her campaign fund without asking why he needed it. Prosecutors called the funds a "reward" for something Shirakawa had done.

At the time, Shirakawa was not in the middle of an election but needed to "retire his debt," Nora Campos told the jury.

Lisa Jensen, initially the campaign manager for Xavier Campos' opponent, Magdalena Carrasco, alleged Nora Campos made a point of trying to get Carrasco not to run, calling her stance "slightly threatening."

During her testimony, Nora Campos said she had only requested a "conversation" with her brother's opponent.

The grand jury hearing only targeted Shirakawa -- who has been linked by DNA to the illegal mailers. He was indicted by the jury on Oct. 28 and faces a trial next year. Those charges come on top of the one-year jail sentence term Shirakawa was given last week in connection to separate counts that he spent campaign and public funds on gambling and lavish dining.

Assistant District Attorney Karyn Sinunu-Towery, the prosecutor in the case, declined to say whether either Campos sibling was being investigated.

"We are just letting the transcript speak for itself," she said. "It just gets curiouser and curiouser."

Contact Mike Rosenberg at 408-920-5705. Follow him at Twitter.com/RosenbergMerc.