In 1971, he wrote the article titled Genocide, published by the Sunday Times, which has been dubbed as an article that "changed history",[1] and recognized as "one of the most influential pieces of South Asian journalism of the past half century"[2] Mascarenhas was born into a Goan Catholic family in Belgaum (then part of the Bombay Presidency), just over 100 kilometres away from Portuguese-ruled Goa, and educated in Karachi.
[5] In March 1971, a civil war erupted in East Pakistan (now Bangladesh) between Bengali nationalists and the Pakistani military government.
When the conflict began, the Pakistani military brought a group of journalists on a 10-day guided tour of East Pakistan to show them how they had successfully quelled the 'freedom fighters.
'[2] By publishing Mascarenhas' piece, the Sunday Times exposed the violence and refuted Pakistan's official line.
"[8] Indian Prime Minister Indira Gandhi stating that Mascarenhas' article led her "to prepare the ground for India's armed intervention".
[8] The Bangladeshi government honoured Mascarenhas's contribution to the nation during the 1971 liberation war by preparing an official list of names.