A FEDERAL grand jury in Philadelphia wants to see an author's notes and papers relating to a recently published book. The author, Antoni Gronowicz, has refused to produce them. You'd think the First Amendment protected him. Judge Louis C. Bechtle does not.

The judge has held Mr. Gronowicz in contempt and levied a fine of $500 a day until he complies. The fine has been suspended by an appellate court until it hears the constitutional question argued. By any traditional reading of the Bill of Rights, it's hardly a question at all.

The U.S. attorney in Philadelphia, Edward Dennis Jr., says the grand jury is not challenging Mr. Gronowicz's freedom of expression but is looking only into a possible case of conventional fraud. And yet it's not easy to see how a grand jury can demand an author's notes without infringing his freedom of expression.

There have been plenty of questions about Mr. Gronowicz's book, "God's Broker." It's a biography of Pope John Paul II, supposedly based on long interviews with him. Whether those long interviews, or any interviews at all, actually took place is now a matter of controversy between the author and the Vatican. The book's publisher withdrew it last summer and denounced it as "fraudulent," according to The New York Times. For a publishing company to denounce and drop one of its own books is a disaster for both book and author.

But whatever the quality or veracity of "God's Broker," they are hardly the proper responsibility of a grand jury. If anyone considers himself to have been defamed by the book, he can sue for damages in the civil courts. Here, instead, the U.S. government has opened a criminal investigation using the broad powers of the grand jury to go after the author's papers.

It is not very difficult to foresee what will come next, if the appellate courts allow this investigation to proceed. There will be other charges of error in other books about eminent public figures. Will there also be other federal grand juries to pursue these allegations with subpoenas demanding authors' notes and interview records, to see whether they have misrepresented their credentials and their research? And perhaps to see whom the authors interviewed, and what each person told them? That is exactly the misuse of the government's criminal investigative powers that the First Amendment was written to prevent.