It’s the case of the missing detective, but the true issue is no mystery.

Nancy Drew, the teen-ager who has been solving mysteries for more than 60 years, has been reported missing from some library shelves, charged with being bad literature.

Several Maine librarians, however, are outspoken against denying children the chance to decide what to and what not to read, especially the tried and true Nancy Drew books that many have grown up reading.

“Public libraries have the responsibility to give children a choice of what to read,” said Donna Rasch, children’s librarian at the Presque Isle Public Library. “It is not our choice to censor books.”

Earlier this month, the New Main Library in San Francisco found itself in the middle of a national controversy after a fourth-grade girl complained to the San Francisco Chronicle about the library’s failure to carry the Nancy Drew series.

Thea Bosselman, 9, wrote to the newspaper after searching fruitlessly for the series in the library. She was told that Nancy Drew books were not good literature because they contain “lazy writing.”

“Money is placed into materials which meet children’s informational needs, expand their multicultural awareness and experiences and which are of a higher quality,” Toni Bernardi, head of children’s services for the San Francisco Library system, was quoted as saying.

The incident drew comment from Nancy Drew defenders all across the country. As a result of the publicity, the San Francisco Public Library agreed to take a fresh look at whether the series should be added to its collection.

According to several children’s librarians in Maine, series books, although labeled junk literature, nonetheless serve to help children become more accustomed to the practice of reading recreationally before moving on to greater challenges.

The literary merit of all series books is dubious at best, but the sameness appeals to kids, allowing them to become comfortable with the characters and writing style.

“You gain something from everything you read,” said Pat Foster, library director at the Ellsworth Public Library, which houses more than 60 volumes of Nancy Drew, still quite popular even today.

Foster, who does agree that Nancy Drew isn’t “great literature,” wishes she had more of the books because they are so popular.

“Do you give kids what they want, or decide what is good literature for them?” asked Anne Mundy, head of children’s services at the Bangor Public Library, which also carries the tales of the teen-age detective. “We give them both. We encourage new and challenging reading, but we also want kids to be happy reading.”

Mundy pointed out that newer versions of series books in the stores and libraries are gaining popularity.

“Goosebumps,” “Babysitter’s Club” and “Sweet Valley High” are among the favorites. Romance novels for adults, which also follow a strict formula, are in libraries and bookstores everywhere.

“But what of these Harlequin romances?” asked Mundy, referring to the popular romance series. “They could be considered mindless reading or lazy writing.”

Literary quality, expanding a child’s horizons and reader demand are factors in what goes on the shelves, said the Maine librarians.

“What is important is that the kids are reading something,” said Foster.