The man was identified as Leonardus Cornelius van der Valck (1769–1845), and used the alias Count Vavel de Versay.
The man presented himself as Count Vavel de Versay and kept the woman’s identity secret, making only clear that they were neither married nor lovers.
The Count – later identified as Leonardus Cornelius van der Valck (born September 2, 1769, in Amsterdam), secretary in the Dutch embassy in Paris from July 1798 to April 1799 – gave her name as Sophie Botta, a single woman from Westphalia; according to Dr. Lommler, the physician who constated her death, she looked about 60 years of age, placing her estimated birth at c. 1777.
The most notable – with very little support from historians though – proposes that she would be the true Marie-Thérèse, daughter of Marie Antoinette, imprisoned in the Temple and supposedly redeemed in 1795 in exchange for French prisoners.
[1] When Marie Thérèse was released from Temple in 1795 and allowed to depart for Austria, Renée Suzanne de Soucy was chosen to accompany her on her journey to the border in Huningue after her mother Marie Angélique de Mackau, who had been the first choice of Marie-Therese, was forced to decline for health reasons.
[1] The alternative suggestion is that "Pierre de Soucy" was in fact one of the daughters of Renée Suzanne de Soucy, dressed as a boy in order to make the travel group less identifiable, as Marie-Therese was estimated to have been exposed to threats not only from anti-royalists but also from agents sent by foreign powers to kidnap her during her journey to the border.