A prominent Cuban neurosurgeon has left Argentina's embassy in Havana, where she had gone to find out whether she could visit her relatives in Argentina.
Dr Molina's son has urged the Argentine president to help
Hilda Molina, wants to see her son, Roberto Quinones, and two grandchildren she has never met.
She said her mother, who was with her, fell ill and they were allowed to stay for a while as guests. Reports that she had asked for asylum proved unfounded.
Mr Quinones said he did not want the case to take on a political slant.
But he said his mother, who has for 10 years been denied a visa to visit him, had been a victim of persecution.
Mr Quinones said his mother visited the Argentine embassy in Havana on Wednesday to check on the status of her travel request.
She was with her 84-year-old mother, who then fell ill with hypertension, he said, and the two spent the night in the embassy "as guests".
Dr Molina was once a Communist Party member, lawmaker and friend of Cuban leader Fidel Castro but broke with the regime 10 years ago, say reports.
"I have no logical explanation," Mr Quinones told reporters in Buenos Aires.
"My mother had a difference of opinion with the government about work-related issues. This was interpreted as something political and she had to quit her job.
"She has suffered from psychological torture and persecution for the simple fact of saying what she thinks and what she feels."
The failure of Dr Molina's application to travel to Argentina prompted Argentine President Nestor Kirchner to write to Mr Castro this month in support of the application.
Plea to president
But Mr Castro suggested that Dr Molina's son - who is married with two children - visit Havana instead.
A spokesman at the embassy in Havana told Efe news agency the diplomatic situation was "tense".
Mr Quinones never wanted the case to take on "political connotations", fearing that a commotion would cause his mother and grandmother to "only be more repressed and besieged".
He urged President Kirchner to telephone Mr Castro to plead the case.