The Act which permitted the censorship of the press and detention without trial was the Rowlatt Act. This legislation, officially known as the Anarchical and Revolutionary Crimes Act of 1919, was passed by the British colonial government in India. It granted the authorities extensive powers to arrest and detain individuals without trial and to censor the press. The Rowlatt Act was met with strong opposition and played a significant role in the Indian independence movement, culminating in events like the Jallianwala Bagh Massacre and further galvanizing the demand for self-rule.

So, the correct option is [3].