A Nobel-prize winning Spanish author, Camilo Jose Cela, was an informer for the fascist regime of General Franco, according to an eminent historian.
Nobel prize-winner Camilo Jose Cela: mercurial and flamboyant
Pere Ysas says he has discovered documents proving Cela offered information about his fellow writers to the country's information ministry.
He even suggested writers he considered ripe for conversion to General Franco's cause, The Guardian newspaper says.
The revelations will fan Cela's reputation as a mercurial character.
Mr Ysas says he found a confidential report written for the country's former information minister and censor Manuel Fraga.
In it Cela reveals the names of a number of writers who had signed a letter condemning police violence against striking miners as members of the Spanish Communist party.
Mr Ysas, who publishes details of the allegation in his book Dissidence and Subversion, says that it seems Cela volunteered to furnish the ministry with the information.
"There is nothing that indicates any previous action calling for his help," Mr Ysas is quoted as telling the London-based newspaper.
"It seems this was something freely done by him."
It appears Cela, whose own work was censored, may have been trying to ingratiate himself with the regime, he said.
The writer won the Nobel prize for literature in 1989 "for a rich and intensive prose, which with restrained compassion forms a challenging vision of man's vulnerability."
He died in 2002 at the age of 85.