Øystein Olsen, governor of Norway’s central bank, is facing more questions from the bank’s supervisory council over exactly how his organisation hired multi-millionaire Nicolai Tangen as the next head of the country’s NOK10.5tn (€911bn) sovereign wealth fund.

The appointment of the London-based Norwegian hedge fund owner as the successor to Yngve Slyngstad – the current chief executive officer of the oil fund’s manager Norges Bank Investment Management (NBIM) – has become a hot topic in Norway following revelations about his relationship with the current incumbent.

Norges Bank announced yesterday afternoon that Olsen gave an account of the process leading to the appointment of the incoming CEO of its NBIM subsidiary at the extraordinary meeting of its 15-strong supervisory council yesterday morning, which had been convened to hear about the matter.

Ølsen, who is also chair of Norges Bank’s executive board, said: “The Supervisory Council has announced that after the meeting it will send over a number of questions to be answered in writing.

“We are looking forward to providing clarification on the matters raised by the Supervisory Council,” he said.

The affair has become a scandal over suspected cronyism, after it came to light that Slyngstad attended an extravagant seminar in Philadelphia last year hosted by AKO Capital founder Tangen, receiving accommodation and a luxury private flight home at Tangen’s expense.

In January, Tangen is also shown to have emailed Slyngstad asking for “a favour” in the form of a chat about details of the top job which had become vacant.

Following revelations the bank made to a Norwegian newspaper on the relationship between Slyngstad and Tangen, Norges Bank on Monday opted to publish a raft of information on its website about the links between the two men, their email exchanges and various information about the recruitment process.

The bank said yesterday that in light of the ongoing discussion between Norges Bank and its panel of overseers, it would wait to issue further responses to questions related to the selection process and Slyngstad’s participation at the seminar in the US, which was entitled “Back to University”.

According to Norges Bank, Slyngstad has stated that, as head of the Government Pension Fund Global (GPFG), not travelling back from the seminar on a scheduled flight covered by Norges Bank was “unfortunate”.