The Constitution of Maldives stipulates that (Art. 132) the Commissioner of Elections, in accordance with the Constitution and Law to organize and conduct the general public vote and the public referendums as may be required by the President to obtain public opinion and (Art. 133) voting in elections and public referendums stipulates in the Constitution and the law shall be by secret ballot.
In the past, referendums were held for a few times. The first Constitutional referendum was held in April 1952 to convert the country from a monarchy to republic. The country’s first president won the election and was overthrown in August the same year. Therefore, the second referendum was held to revert to manarchy status. In 1968, the third referendum on the same issue was held and Maldives became a republic again. In 2007, a constitutional referendum was help to decide on whether the country should have a presidential or parliamentary system.
Asian LII, Constitution of the Republic of Maldives 1998, http://www.asianlii.org/mv/legis/const/1998/1.html.
Wikipedia, Maldivian constitutional referendum 1952, https://en.wikipedia.org/wiki/Maldivian_constitutional_referendum,_1952.
Wikipedia, Maldivian revolt referendum 1968, https://en.wikipedia.org/wiki/Maldivian_constitutional_referendum,_1968.
Wikipedia, Malgivian constitutional referendum 2007, https://en.wikipedia.org/wiki/Maldivian_constitutional_referendum,_2007.