Dr David Kelly "jumped" at the mention of Alastair Campbell's name at the height of the Iraq dossier row, the weapons expert's daughter has told the inquiry into his death.
Ms Rachel Kelly recounted a conversation with her father in July when he seemed to be under "severe stress".
The pair had gone out for a walk in Oxford as the search for the then-unnamed source of BBC reporter Andrew Gillian's story intensified.
Dr Kelly had informed his bosses at the Ministry of Defence that week he had met Mr Gilligan and that he might be the source of the story on BBC Radio 4's Todayprogramme the British government had "sexed up" the dossier on Iraqi weapons.
Ms Kelly (30), giving evidence via video link, said she had noticed a change in her father's demeanour, that he had become increasingly withdrawn in the weeks up to his apparent suicide.
Recalling their discussion she at first assumed his mood had something to do with his work in Iraq, but then she recalled a television interview that Downing Street's director of communications had had on Channel 4 News a few days earlier, on June 27th.
"I asked him if the situation in the media, about Alastair Campbell, was affecting him," Ms Kelly said. "His reaction alarmed me greatly. . . . He jumped, I felt. He said 'No, not really'.
"I felt that I had intruded. He was very quiet, very pale. He just seemed to have the world's pressures on his shoulders. He seemed to be under severe stress," she said.