Alexander Grothendieck's "stolen" correspondence in 1985?

Question

On the website that now displays the part of Grothendieck's archives that had been held at the University of Montpellier, it is mentioned that:

Dans une lettre adressée à Monsieur Lefranc datée du 13 octobre 1985 (voir cote 183/97), Grothendieck évoque la disparition de sa correspondance allant de S à Z. Il affirme que ces documents se sont volatilisés à l’occasion du « sac » de son bureau la même année.

(Own translation: In a letter addressed to Monsieur Lefranc dated October 13, 1985 (see reference 183/97), Grothendieck addresses the disappearance of his correspondence from S to Z. He asserts that these documents vanished on the occasion of the "burglary" of his office that same year.)

I'm interested in facts about this.

• Is it true that these letters were stolen?

• If so, then who might have been the perpetrators and what might have been their motives? And is it then possible that historically interesting letters, from perhaps Tate or Serre, might have been lost?

Answer 1

The Grothendieck Circle site suggests a more innocent explanation for the loss these letters.

Having left Montpellier in 1984....

In May of that year [1985] a secretary informed him that his office on the fourth floor of the institute had been cleared out. Seeing this incident as an egregious example of the general decline of mores, an outraged Grothendieck appealed to M. Lefranc, the director of the institute, to the president of the university, to Mme. Charles, the person directly responsible for issues concerning offices, and, in an open letter, to his colleagues from the mathematical institute. (In another letter written later, he excused himself for having, in his haste, omitted to send the open letter to the staff and the graduate students.)

In her answer, Mme. Charles described the situation from her point of view, and pointed out that Grothendieck lived very far away, was difficult to reach, and had not been seen at the institute for a long time. A meeting of lecturers from the institute (UER 5) took place in the presence of Grothendieck, and the director of the institute sent him a collective letter of apology: “Les enseignants de Mathématiques présentent leurs excuses à Monsieur Grothendieck”.