There was intelligence Fishmongers' Hall attacker Usman Khan "might commit an attack" around the time he was released from prison for a terror offence, an inquest jury has heard.
Jonathan Hough QC also told the inquests into the deaths of Cambridge graduates Jack Merritt and Saskia Jones there was a suggestion their killer tried to radicalise other inmates before his release.
Khan, 28, from Stafford in the West Midlands, attacked Mr Merritt, 25, and Ms Jones, 23, at a prisoner rehabilitation event near London Bridge on November 29 2019, a year after his release from jail having been convicted of planning a jihadist training camp.
Mr Hough told jurors that there was, as recently as summer 2017, intelligence that Khan was "the main inmate in the area for extremist views and others".
However Reverend Paul Foster, chaplain at the category A Whitemoor Prison in Cambridgeshire, told the inquests it would be a "surprise" to him if there was intelligence against Khan.
He said Khan had engaged positively with programmes looking at his offending and the impact of his crimes, but said it was possible he may have been "conned" by him.
Mr Foster told the inquests: "He had conversations with me about wanting to change and make a fresh start – to pay more attention to the ripple effect of his actions."
Mr Hough asked: "Would it have surprised you that, around the time Usman Khan was … engaged in victim awareness, there was intelligence he was trying to radicalise other prisoners?”
Mr Foster said it would.
Mr Hough also said that, at the time of his release, there was intelligence that Khan might commit an attack.
Mr Foster replied: "That would be a surprise. If that intelligence is correct, he was obviously presenting himself in a way that was likely to deceive the likes of myself and others."
He added: "I’m open to say I am wrong, and it is possible I have been conned."
Mr Foster also said Khan had spoken "openly and emotionally" during a discussion session with a victim of crime.
He added: "We were being presented with a lot of positive things about his behaviour – even some of the prisoners were telling me … in one instance a chap lost his son to a murder and Usman was the person at his door offering his condolences and asking if he could help."
The chaplain, who worked with prisoners of all faiths, described one session with Khan in which he professed “some shame” about the impact his crime had on the Muslim community.
"He appeared to show remorse for what he had done," Mr Foster said.
The jury inquests into the deaths of Mr Merritt and Ms Jones are taking place before coroner Mark Lucraft QC at Guildhall in the City of London.