Andy Burnham has described the death of former Cambridge professor Jason Arday as "a tragedy on so many levels", as he called for a "moment for reflection".
Arday was found dead at an address in Battersea, south London, on Friday afternoon.
"It's not a moment for any rushing to judgement. It's a moment for reflection, I would say, reflecting on how things came to this," the prime minister told broadcasters during a visit to Cornwall.
In a statement issued by his publisher Simon & Schuster UK, Arday's family said they were "in shock to have lost this amazing father, partner, brother, uncle and son".
They said a "campaign of misinformation" had been too much for him.
Arday, 41, resigned as a Cambridge professor of sociology of education last week after allegations of plagiarism and questions about some of his achievements. He had denied the claims.
A friend told the BBC Arday had described feeling "destroyed" and had told him his authorisation to travel to the US had been revoked.
Eamonn McCrystal, who became his friend at St Mary's University, Twickenham, tried to reassure him what he was going through would pass, but Arday replied "it does not feel like it will."
McCrystal told the BBC "He was the nicest person. So kind and such a gentle soul.
"We shared an office at university, when I set up the student radio station, and he used to speak on the station a lot."
"I'm in shock, I can't believe it."
The University of Cambridge vice-chancellor Prof Deborah Prentice led the tributes, saying the faculty was "desperately saddened" to learn of his death.
"Our heartfelt sympathies go to Jason Arday's family and friends at this incredibly difficult time," she added.
Education Secretary Lucy Powell said she was "deeply shocked and saddened" and urged people to "remember there are real people with loved ones involved".
Mayor of London Sir Sadiq Khan said Arday was subjected to unrelenting media scrutiny.
He said he had faced "an unacceptable public hounding and campaign of abuse" and was the victim of "a pernicious public shaming".
"His death was a tragedy, but once again it should be a wake up call for all of us," he posted on X.
Jo Grady, general secretary of the University and College Union said the "level of harassment he suffered and the racism he was subjected to has been sickening" and "must be investigated".
Lord Paul Boateng, who became the UK's first black cabinet minister in 2002, told BBC Newsnight he was "horrified, shocked and deeply saddened".
"Racism in academia is a fact of life and needs to be addressed," he added in a written statement.
In a statement on Saturday, National Education Union (NEU) general secretary Daniel Kebede said Arday had been subjected to "a public and brutal takedown that unleashed a tirade of racism".
"The effect has been chilling. It tells black people and others from underrepresented backgrounds that entering prominent public positions will make you a target," he said.
Director of the Autism Research Centre at the University of Cambridge, Prof Simon Baron-Cohen told the Today programme Arday had been "bombarded by every media outlet to paint him as a fraud".
"He was an incredibly, kind and gentle and caring man," he said.
He spoke to Arday the morning of his death, and said the academic had felt unable to leave the house.
"He has experienced what he described as a campaign against him, for the last three years," he previously told BBC News.
"What he was saying to me was 'they've destroyed my life' - it's not clear who they were but I think he was referring to the media.
"The personal attacks on him have been so immense."
Speaking to BBC Newsnight, Professor of Black Studies Kehinde Andrews, a friend of Arday, described him as "very down" after resigning from Cambridge.
"He was very upset. He felt that there was no way out. He effectively wasn't leaving the house. He had lost a lot of weight," Andrews said.
"There should be a wakeup call to just how bad black academics actually have it in academia."
Labour MP Bell Ribeiro-Addy also told the programme "the idea that an academic would be dragged through this amount of media scrutiny is unheard of".
Shadow communities secretary Sir James Cleverly said he was angered by the "tragic" death and said "a number of people at a number of academic institutions have serious questions to answer".
Arday had denied plagiarism - but admitted errors in his work - and said the recent controversy had led to "an unrelenting level of public scrutiny and personal attack".
The row first erupted after another academic - self-defined "race realist" Nathan Cofnas, who was sacked from his Cambridge role in 2024 - said he found numerous instances of plagiarism in the professor's work.
Arday said some errors in his early academic work arose because of his autism, as he relied on using mimicry to make sense of information. Similar scrutiny would find similar errors in work by other academics, he said.
Questions were also raised about parts of his life story, including that he ran 600 miles in six days and that he had raised £5.5m for charity.
He later said the run was actually completed over a 12-day period to allow for rest days - and that the huge sum was raised with the help of others.
Arday's appointment as Cambridge's youngest ever black professor at the age of 37 in 2023 was hailed at the time.
Announcing his resignation last week, Arday said the "personal cost" of the scrutiny of him had become "too great".
He said: "While criticism is an inevitable part of academic life, what I have experienced has gone far beyond scholarly disagreement.
"The relentless accusations, speculation and public commentary have taken a profound toll on me and on those I love."
He stressed that his resignation should not "be mistaken for an acceptance of the narratives that have surrounded me".
Earlier this week, Cambridge announced an independent investigation around the circumstances of Arday's appointment.
Liverpool John Moores University - which awarded Arday his PhD in 2015 - concluded that he had not plagiarised work.
In a statement on Saturday, a spokesperson for the university said it was "saddened to hear of the tragic loss of Professor Jason Arday".
