Confidential papers on anti-depressant drug Prozac that went missing during a murder case have been handed to the US drug regulator by a UK medical journal.
Prozac is used to treat depression
The documents, belonging to Eli Lilly, the makers of Prozac, included details of clinical trials of the drug, the British Medical Journal said.
They reportedly disappeared during a lawsuit following the shooting of eight people by Joseph Wesbecker.
Eli Lilly said the papers contained no new information.
Mr Wesbecker, who was on Prozac, shot eight people dead in 1989 in the US.
Another 12 people were injured during the shooting spree at a printing plant in Louisville, Kentucky.
The 47-year-old then shot himself.
In 1994, the relatives brought a civil case against Eli Lilly.
The company subsequently won the case but was later forced to admit that it had made a secret settlement with the plaintiffs during the trial, which meant that the verdict was invalid, the BMJ reported.
Dr Richard Kalpit, the clinical reviewer at the US Food and Drug Administration, the US drugs regulator, who approved the drug, told the BMJ he was not given the data included in the documents.
"These data are very important. If this report was done by Lilly or for Lilly, it was their responsibility to report it to us and to publish it."
Recent research has suggested children who use Prozac are at greater risk of suicide.
And earlier this month the Medicines and Healthcare Products Regulatory Authority said analysis of both published and unpublished data by experts on the Committee on Safety of Medicines showed "a modest increase in the risk of suicide from SSRIs [such as Prozac and Seroxat] compared to placebos [dummy pills]" in adults.
The FDA is now reviewing the papers, which were given to the BMJ by an anonymous source.
BMJ deputy editor Dr Tony Delamothe said the journal had handed the confidential drug company documents to the FDA as it believed healthcare decisions need to be made using all the information available.
"The BMJ is committed to ensuring that results good, bad, or indifferent are reported."
Eli Lilly chief medical officer Alan Breier said the documents revealed no new clinical or scientific information and the information had already been shared with the regulatory authorities.
"Lilly believes in full and appropriate disclosure of clinical trial data and recently underscored this commitment through the launch of Lilly's clinical trial registry database."
And he added: "Lilly is greatly concerned that a reputable medical journal has relied on an anonymous source and published data without validating the information at hand or conducting standard peer review."