An Argentine prosecutor dead under mysterious circumstances. His case against the president thrust spectacularly into the national spotlight. These events -- are they fact or fiction?

Reality collides with make-believe in "El Fiscal," a Spanish-language political-fiction thriller that hit bookstore shelves last week and is based on the real-life death of Alberto Nisman, the Argentine prosecutor who died suspiciously in January while pursuing a case against President Cristina Kirchner.

The novel, which Argentina's Emece publishing house says was "written at a frenetic pace" so that it could appear just three months after Nisman's death, tells the story of the last hours in the life of fictitious prosecutor Antonio Lerman and the events leading up to his demise.

"'El Fiscal' is an electrifying political fiction thriller, in the same vein as John le Carre spy novels and classic film noir," Emece said on its website.

"The authenticity takes your breath away."

Circumstances surrounding the death of Nisman, who was found with a gunshot wound to the head, have kept Argentina on tenterhooks amid mass debate and investigation as to whether it was a case of murder or suicide.

Nisman was found dead in his Buenos Aires apartment on the eve of congressional hearings where he was due to present allegations about the president.

Four days before Nisman's death on January 18, he filed a report accusing Kirchner, Foreign Minister Hector Timerman and other figures close to the government of protecting high-ranking Iranian officials, accused of orchestrating a deadly 1994 bombing at a Buenos Aires Jewish center.

"El Fiscal," whose full title in English translates to "The Prosecutor: A Fiction Too Similar to Reality," was written by a mystery author under the pseudonym RS Pratt.

Emece director Ignacio Iraola told Clarin newspaper that the idea for the book "arose while chatting with the author the day of Nisman's death."

"The author called me to discuss the issue. Later that night, this person read Nisman's full report and called me back the next day saying -- directly -- that the case was a le Carre novel," Iraola said in the article out Saturday.