Longuinhos Rabindranatha Tagore Domingues de Castro Monteiro[1][2] (born 20 December 1968) is an East Timorese jurist, administrator and politician.

[2] After attending school in Dili until 1987, Morteiro studied law at the University of National Education (Indonesian: Universitas Pendidikan Nasional (UNDIKANS)), in Denpasar, Bali, Indonesia, from 1988 to 1994.

[2] Monteiro was part of the first group of lawyers hired by the United Nations Transitional Administration in East Timor (UNTAET) after it assumed control of the territory in 1999.

On 7 January 2000, the United Nations representative in East Timor, Sérgio Vieira de Mello, installed Monteiro as an investigating magistrate.

One critic of the appointment, Luis de Oliveira Sampaio, executive director of Judicial System Monitoring Programme, a non-governmental organisation, stated that "We would prefer the commander to come from inside the institution ...".

Another critic, Arsenio Bano, an Opposition member of the National Parliament, made a similar statement, and also claimed that Monteiro had "... not performed very well ..." as Attorney General.

The following day, Monteiro was subjected to a first interrogation in Dili, and was detained, by the Scientific Police for Criminal Investigation [pt] (PCIC), for alleged possession of a prohibited weapon.

Additionally, the President of East Timor, José Ramos-Horta, reacted to the detention by sending a message to Lusa, a Portuguese news agency, stating that "Some gentlemen claim for themselves powers that they don't have, and trample all the principles and values that guide democratic societies ..."[13] Monteiro is married with two sons.