Supreme Court of Justice in Mexico City
A man takes part in a rally supporting the legalization of marijuana in front of the Supreme Court of Justice in Mexico CityGetty

Mexico's Supreme Court has ruled that growing, possessing and smoking marijuana is legal under the country's constitution, opening the door to possible decriminalisation or even legalisation in one of the world's most notorious narco states.

The Latin American country's Supreme Court ruled by a margin of four on a five justice panel that smoking marijuana was guaranteed by the right of free development of personality.

A man smokes marijuana
A man smokes marijuana during a rally in front of the Supreme Court of Justice in Mexico CityGetty

At the moment the ruling only covers four individuals from a pro-cannabis group who wanted to create a marijuana club, of the kind often seen in the United States. However, the court is currently waiting to rule on five other similar cases which could open the flood gates to legalisation.

Reuters news agency quoted Mexican Supreme Court Justice Arturo Zaldivar as saying the vote was not an indication that marijuana was harmless but rather that "prohibition is a disproportionate measure."

In Mexico, where thousands are killed every year in connection to drug trafficking and related violence, the development is significant. The country legalised gay marriage through similar court rulings.

However, full legalisation faces an uphill battle. Mexican president Enrique Pena Nieto has said via Twitter that the government will explain the scope of the ruling. He has set out his position as diametrically opposed to a relaxing of cannabis legislation.

The plaintiff's were well aware of the political implications of their case. The Mexican Society of Responsible and Tolerant Auto-consumption (SMART) is hoping to break the back of the drug cartels by cutting off their illegal revenue streams. One of the lawyers has said on the record that he has never smoked a joint in his life and doesn't intend to.