"possible clues" is a correct and usable phrase in written English.
It can be used when talking about evidence that might help solve a problem or mystery. For example, "The police were searching the crime scene for possible clues."
A site of possible clues, of evidence left behind.
He said the results could provide "possible clues" to the effects of the oil spill on other dolphins in the northern Gulf of Mexico.
With no one around to ask how a mummified infant came to be locked in an airtight cedar box inside the McClure home, neighbors acquainted with the sisters searched their memories today for possible clues.
F.B.I. agents yesterday questioned a leading proponent of the theory that the anthrax attacks were the work of someone linked to a federal laboratory or contractor, asking her about possible clues to the culprit's identity.
"She always had a thing for exotic animals," said Carol Anderson of Mendham, Ms. Bousquet's sister, looking for possible clues that might have led Anne to spend her adulthood in Africa.
Narcotics investigators and detectives from the Manhattan South Homicide Squad and the Midtown North Detective Squad were also sifting yesterday through records and address books found in Ms. Stahl's apartment, looking for possible clues to the killers' identity, officials said.
Others involve the fact that Michaels craft stores, part of a chain, have been at or near three shopping center shootings; the police have combed employee and customer records for possible clues.
The new inquiry included looking for any possible clues and textual "finger prints" on a Chinese document that the C.I.A. got in 1995 and had long resided at the heart of the spy case.
He needs the news media to motivate the public for possible clues, he emphasizes, yet he is increasingly concerned that journalists rushing to crime scenes and second-guessing the police might jeopardize the investigation.
Now another sign has emerged offering possible clues to Mrs. Clinton's Murdoch status: Mr. Murdoch's daughter Elisabeth is holding a fund-raiser at her London home this month for Senator Barack Obama of Illinois.
And this leads to possible clues, including a theory that D.P.I.C.M. vanes underwent experiments in Germany in the 1970s, and that that technology migrated from there, to any number of other countries.
