When archaeologists start digging on an olive tree-covered mountainside today, they may finally unearth the truth about one of Spain’s most enduring literary riddles.

Guarded round the clock, a portion of land about the size of half a football pitch near the southern city of Granada may contain the final resting place of Federico García Lorca. One of the country’s greatest poets and dramatists, Lorca was shot dead along with three other men by gunmen loyal to General Francisco Franco a month after the start of the Civil War in 1936.

His crime was to be homosexual, and to produce work that enraged conservatives. In death he became a symbol of Franco’s repression — a symbol that endures today.

More than 70 years after the poet’s murder, the location of his grave remains a mystery. Projects to locate and identify his remains, and then offer a more appropriate resting place for a literary giant, have long been opposed by his family.

However, the passing of the Law of Historical Memory, in 2007, gave relatives of Franco’s victims state assistance to unearth the remains of their loved ones. The family of Francisco Galadí, an anarchist bullfighter thought to have been shot alongside Lorca, requested that an area of land where the men may have been buried should be searched.

Lorca’s family has now relented and agreed to provide DNA samples to distinguish the poet’s bones from those of the three other men. Lorca was one of about 130,000 people historians believe were killed by Franco’s death squads during the war and in the years that followed.

Their bones still lie undiscovered in graves across Spain. Ian Gibson, a biographer of Lorca who located the mountainside site in 1966, told The Times: “He is the most famous ‘disappeared’ person. If they locate his remains it will bring attention to the genocide. It is so long since the Civil War and Franco is dead but Spain has not addressed this.”

The site is marked with flowers, and visitors regularly go to pay tribute. For Laura García Lorca, the poet’s niece and president of the Federico García Lorca Foundation, the dig will be an emotive moment: “We will give DNA if it is necessary, but this will be very difficult and disturbing for the whole family,” she said.

Such is the sensitivity surrounding the dig, that archaeologists have been banned from taking mobile phones to the site to stop pictures from appearing on the internet.

Born into a middle-class Andalusian family in 1898, Lorca attracted the ire of the Right during the 1930s with works such as The House of Bernarda Alba, Blood and Yerma — in which a peasant woman murders her husband and denies God.

After the death of Franco in 1975, Spain entered into a “pact of forgetting”, ignoring bitter memories in an effort to move forward.

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