Iraq weapons expert Dr David Kelly reportedly warned of "many dark actors playing games" in an e-mail sent hours before he bled to death from a slashed wrist.
Dr Kelly's e-mail gave no indication he was depressed
The message, sent to a journalist, appeared to refer to officials within the Ministry of Defence and British intelligence agencies with whom he had sparred over interpretations of weapons reports, according to the New York Times.
Dr Kelly disappeared two days after being questioned by the Commons foreign affairs select committee.
But his e-mail gave no indication he was depressed and said he was waiting "until the end of the week" before judging how his appearance before the committee had gone, the newspaper said.
The 59-year-old had told MPs he had spoken to BBC reporter Andrew Gilligan but did not think he was the main source for his report that Downing Street communications director Alastair Campbell "sexed up" a dossier setting out the case for war in Iraq.
His body was found at 0920 BST on Friday in a wooded area at Harrowdown Hill, near Faringdon.
Two days later BBC director of news Richard Sambrook revealed that the scientist had been the principal source for Mr Gilligan's report.
On Thursday, before leaving his Oxfordshire home for the last time, Dr Kelly had worked on a report he said he owed the Foreign Office and sent
some e-mails to friends, his wife, Janice, told the New York Times.
The newspaper said a second e-mail, sent by Dr Kelly to an associate, was "combative".
In it, the Ministry of Defence adviser said he was determined to overcome the scandal surrounding him and was enthusiastic about the possibility of returning
Mrs Kelly told the paper her husband had been under enormous stress "as we all had been", but she had no indication he was contemplating suicide.
Police investigating Dr Kelly's death have taken away his home computer for examination.