From Napoleon Bonaparte: An Intimate Biography by Vincent Cronin, 442-443:
'...Bourrienne had what Napoleon called 'a magpie's eye' and began to embezzle. When Napoleon gave Hortense a Paris house as a wedding present, Bourrienne paid half a million francs for the house but charged it to Napoleon as one million. He passed on news of Napoleon's doings to an interested party for 25,000 francs a month. Napoleon had to dismiss him in 1802, but sent him in 1804 to Hamburg as charge d'affaires. Here Bourrienne carried on a profitable trade in forged passports and illegal exactions. A special investigating commission found, in 1810, that Bourrienne had embezzled 2 million francs. Napoleon removed Bourrienne from his post and ordered him to pay back half the sum.'
'...A publisher named Ladvocat persuaded him to write his Memoirs as a way of paying his debts, brought him to Paris and installed him in a small room. But Bourrienne wrote nothing. All he did was to make notes on which, later, the first two volumes were based. As for the eight other volumes, they were ghosted by Maxime de Villemarest, a failed diplomat turned journalist, an indefatibible 'ghoster' of Memoirs...and an admirer of Talleyrand, whose Life he was also to write. In 1834 Bourrienne died in a lunatic asylum.'