A prominent Cuban-American journalist has described An Post's decision to feature Che Guevara on a new stamp as "objectionable".
An Post unveiled the controversial €1 stamp on Friday.
Ninoska Perez of Miami 710 radio said that Che Guevara was considered a mass murderer and should not be honoured.
Speaking on RTÉ's Morning Ireland, Ms Perez said that the stamp should be abolished, adding that the stamp of a country should feature people whose lives are worth celebrating.
The stamp, which was released to mark the 50th anniversary of the revolutionary’s death, has provoked strong criticism on social media with some members of the public arguing that Guevara's legacy makes him an inappropriate subject for inclusion on an Irish stamp.
The stamp features the famous image of 'Che' by Dublin artist Jim Fitzpatrick, which appears on T-shirts, posters, badges and clothing worldwide and is now rated among the world’s top ten most iconic images.
The Department of Communications said that the decision to issue the stamp had been approved by the government in 2015.
A spokesperson said: "Subject matter for stamp designs are presented to Government in advance. This particular subject matter (Che Guevara) was submitted and approved by Government in December 2015 as per normal procedures."
The artist behind the image has said he was deeply honoured to have one of his own works used to mark the 50th anniversary of Guevara's death.
Speaking on RTÉ's Six One, Jim Fitzpatrick said it is extraordinary that the stamp features the revolutionary, given what he described as the "bad propaganda that is out there about him".
He said Guevara remains a "hero" of his.
Mr Fitzpatrick said Guevara was a martyr.
He said: "He was a man who could've sat happily as the governor of the central bank of Cuba and lived happily ever after in luxury, who gave it all up to fight for the poor and dispossessed in the poorest part of Latin-America, where he'd no support; the communist party refused to support him. He was captured as a prisoner of war and then he was executed."
Ms Perez said the only Irish link Che Guevara has is that some of his family came from Ireland.
She said: "I really don't know what it is that people find that there is to celebrate about the figure of Che Guevara. I would love to see that stamp abolished. What does Ireland think they are doing by putting Che Guevara on a stamp? This is objectionable."
Ernesto 'Che' Guevara was born on 14 June 1928 in Rosario, Argentina.
His family were prosperous and had aristocratic roots, but had left-wing sympathies. His father was Ernesto Guevara Lynch, a civil engineer of Irish descent.
A quote from Guevara Senior features on a First Day Cover (FDC) envelope produced to accompany the stamp. It says "... in my son's veins flowed the blood of Irish rebels".
Che Guevara assisted Fidel Castro in overturning the Cuban government in the late 1950s. He then held key political offices during Castro’s regime.
He was executed by the Bolivian army on 9 October 1967.
With his death, and assisted by the popular artwork, Guevara the Marxist revolutionary went on to become a cultural icon.