In the United States, so-called “birther” controversies roiled the presidency of Barack Obama, who some – including most prominently current presidential candidate Donald Trump – claimed was actually born in Kenya. Similar theories could complicate the presidential campaign of Texas Senator Ted Cruz, who was born in Canada to U.S. citizen parents.

Now it seems that some of Venezuela’s opposition legislators are adopting a birther conspiracy of their own.

Members of Venezuela’s National Assembly officially opened an investigation Thursday into the birthplace of President Nicolás Maduro, who some have asserted was born not in Caracas but in the Colombian border town of Cúcuta.

Venezuela’s constitution requires that the president be Venezuelan by birth and not hold other nationalities.

But such claims are nothing new. For years, rumors have circulated that Maduro was born in Colombia, and Colombian officials with the National Civil Registry have produced what appears to be a Colombian citizen identification card belonging to Maduro’s mother, who was born in Cúcuta.

Venezuelan officials, however, say that suggestions the president may have been born on Colombian soil are baseless. The Venezuelan National Electoral Commission has previously produced what they say is Maduro’s birth certificate listing Caracas as his birthplace.

A leaked confidential U.S. State Department document from 2006 also states that Maduro was born in Caracas.

But that hasn’t stopped conspiracy theorists from speculating.

According to Maduro’s supporters the Assembly investigation is simply the latest opposition party attempt to discredit Venezuela’s socialist president after winning a majority in December elections for the first time in 16 years.

Opposition Assembly members have openly stated that they will seek to remove Maduro from office before the end of his term.