Two senior Brazilian officials are due to arrive in Britain to question the commission investigating the shooting of Jean Charles de Menezes.
The Brazilian Foreign Relations Ministry said the new information about the case of killing, and "shocking" photos of Mr Menezes' body had heightened Brazil's "sense of indignation".
It said Wagner Goncalves, from Brazil's Federal Prosecutor's Office, and Marcio Pereira Pinto Garcia, of the Ministry of Justice, hoped to get "a number of matters" clarified, BBC reports.
Wagner Goncalves, of the Brazilian prosecutor's office, and Justice Ministry official Marcio Pereira Pinto Garcia will arrive in the U.K. capital today, Brazil's Foreign Ministry said on its Web site. During the visit, they plan to meet with police officials and members of an independent panel investigating the July 22 shooting of the Brazilian electrician, and will seek "broad clarifications" about the case, the ministry said.
The Independent Police Complaints Commission (IPCC) said the officials would not meet with its representatives until Wednesday.
The men will also meet other officials, including the Met's Deputy Assistant Commissioner John Yates, who flew out to Brazil after the shooting to speak to the Menezes family.
The 27-year-old Brazilian was killed by police at Stockwell Tube station on 22 July, after officers wrongly linked him to the attempted bombings a day before.
Leaks from the Independent Police Complaints Commission have cast doubt on claims Mr Menezes resisted arrest.
Meanwhile, supporters of his family plan a protest vigil at Downing Street.
The Jean Charles de Menezes Family Campaign group's vigil marks the fact that it is a month since the electrician was shot.
On Sunday, a spokesman for Tony Blair said he fully backed Metropolitan Police Commissioner Ian Blair over his handling of the case.
Mr Menezes' family want Sir Ian to resign for incorrectly linking the shooting to the attempted bombings early on.
On the day of Mr Menezes' death, Sir Ian said the shooting was "directly linked to the ongoing and expanding anti-terrorist operation".
Sir Ian has told the News of the World it was 24 hours before he learned the Brazilian was wrongly shot dead.
The family's lawyer has expressed "incredulity" that he made statements without knowing facts.
On photo: Iar Blair (BBC).