Pablo Neruda was Chile's greatest poet and died less than two weeks after a military coup in his country in 1973.
His family maintains that he died of advanced prostate cancer, but his body is to be exhumed as part of an inquest into allegations that he was poisoned.
Words from one of his poems have been found at Bay of Sannick in Caithness.
Edgar White came across the carvings close to his home. He hopes to find out who carved the words and why.
He said: "While examining the Old Red Sandstone reefs at the west end of the remote beach at Bay of Sannick near to John O'Groats, I became aware of the carving on an adjacent reef being exposed as the tide dropped.
"Subsequent research revealed it to be the whole of number XVII of Pablo Neruda's suite of poems, Las Piedras del Cielo - Stones of the Sky."
Mr White added: "Who carved it is still a mystery, but it is a supremely artistic work, executed under the difficult tidal conditions off the shore of the Pentland Firth.
"Time for working would have been limited to the period between tides."
Mr White said the words may have been carved in 2004, the 100th anniversary of Neruda's birth. He said there was a celebration of the poet's life in Edinburgh that year.
Last month, a court in Chile set a date for the exhumation of Neruda's remains as part of an inquest into his death.
International experts will begin their examinations on 8 April to determine how the poet and long-standing Communist Party supporter died.
In 2001, Chile started investigating allegations by his former driver, Manuel Araya Osorio, that the poet had been poisoned.
Neruda's body is buried next to his wife Matilde Urrutia in Isla Negra, 120km (70 miles) west of the capital Santiago.
He had been a friend of Chile's socialist President Salvador Allende.
Neruda died 12 days after Allende was overthrown in a military coup and Augusto Pinochet. The poet's work was banned under the Pinochet regime.
President Allende's death was also the subject of an investigation.
In December 2011, after his remains were exhumed, it was confirmed that Allende committed suicide, and was not killed by soldiers who stormed the presidential palace during the coup, as some had argued.
A poem by a Nobel Prize-winning poet at the centre of an investigation into his death has been found carved into rocks at a remote Scottish beach.