Previous Minister for Enterprise and Energy Maud Olofsson has said that she approved the deal at the time, despite being warned about the risks. Now, Anders Borg has said that the Department of Finance was aware of the problems too.
"Yes, of course we in the Department of Finance raised a number of questions and those questions were also reflected in the inquiries made by the Ministry of Enterprise, Energy and Communications," Borg told Swedish Radio.
"Namely, whether the company would be able to meet the profit demand given the size of the investment. That question was then put to the board which judged that it would," said Borg.
Vattenfall's purchase of Nuon was Sweden's biggest business deal. Many within the government warned against it.
Newspaper Svenska Dagbladet recently published excerpts from emails in which officials from the Ministry of Enterprise, Energy and Communications warned that the deal would become a burden for Vattenfall and would not meet the state's profit demands.
Those predictions turned out to be true. Vattenfall paid SEK 89 billion for Nuon and has reportedly had to depreciate the value of the company by SEK 15 billion.
Borg does not think that Olofsson or the government bear any responsibility for the deal.
"The board is appointed to take commercial decisions of this kind and because she posed those questions to the board the responsibility is theirs."