The Crown Prosecution Service (CPS) has been asked to review evidence into the death of a railway worker who was reportedly spat at by a man claiming to have coronavirus.
British Transport Police (BTP) concluded last week Belly Mujinga's death was not linked to the incident and closed the case.
More than a million people have signed a petition in support of Ms Mujinga.
BTP said it requested the review in light of the "wider public interest".
Ms Mujinga , 47, died with Covid-19 on 5 April, a few weeks after an incident at London's Victoria station.
BTP interviewed a 57-year-old man but said "there was insufficient evidence to support a prosecution based upon the allegation that the man spat deliberately on Mrs Mujinga or said that he had the virus".
The man also gave a negative antibody test, showing he had never had the illness, and the force subsequently decided not to refer the case to the CPS.
In a new statement on Friday, BTP said it had invited the CPS to conduct an independent review of the available evidence, and whether there were any further lines of inquiry.
BTP said it understood the depth of feeling over the case and that there were further questions over how it was decided there was insufficient proof of a crime to justify a prosecution.
"We can assure the public that we have comprehensively reviewed all the available evidence and have not identified any offences or behaviour that meets the threshold for prosecution," it said.
The petition seeks justice for the family of Ms Mujinga, and her husband Lusamba thanked those who have signed it, saying they had been on a "rollercoaster of emotions".
The public reaction to the case being closed took the family by surprise, he said, adding it had come amid anger over the killing of George Floyd in the US.
He said: "On Wednesday, thousands of people protested in London to cry it loud that black lives matter.
"Black lives do matter. Belly's life mattered.
"It mattered to me, to our daughter, our friends and family, to Belly's colleagues, and now it matters to many thousands of you out there."
Angie Doll, managing director of Southern Railway and Gatwick Express, said: "Our hearts go out to Belly's family who we continue to offer our deepest sympathies to.
"While the conclusion of the BTP investigation found no evidence of spitting, any loss of one of our dedicated colleagues from coronavirus is one too many.
"Our absolute focus remains on keeping all of our colleagues safe, and we continue to follow all government health advice to protect them."