Brazilian photojournalist Sebastiao Salgado has sent an open letter to President Jair Bolsonaro – signed by celebrities like Brad Pitt and Madonna – calling for “urgent measures” to save the indigenous peoples of the Amazon from the coronavirus pandemic.

“The indigenous peoples of Brazil face a serious threat to their own survival with the emergence of the Covid-19 pandemic,” said the letter, backed by an online petition which has so far gathered around 50,000 signatures.

The 76-year-old photographer has won numerous international awards for his portrayal of the poor across the world, most recently turning his focus on the peoples of the Amazon rainforest basin.

“Five centuries ago, these ethnic groups were decimated by diseases brought by European colonisers,” said the letter, signed by a list of celebrities including Paul McCartney, Richard Gere and Meryl Streep.

“Today with this new scourge spreading rapidly throughout Brazil,” the Amazon’s indigenous people “may disappear completely since they have no means of combating Covid-19”.

The stars appear in a video by Brazilian director Fernando Meireles, which features Salgado calling on Bolsonaro to put an end to economic intrusion into the lives of the Amazon peoples, and to “guarantee their protection”.

“Brazil owes a debt to its first inhabitants. It is time to do what should have been done a long time ago,” says Salgado.

The Brazilian state of Amazonas, home to most of the country’s indigenous people, is one of the regions worst affected by the pandemic, with more than 500 deaths to date according to the health ministry.