According to the document, concerns over possible extremist ties emerged during the course of the UN group’s investigation of Khaire’s activities with Soma that allegedly "related to facilitating bribery of public officials in Somalia”. The monitoring group said it "remains concerned by Mr. Khaire’s possible links to East African extremist groups, including but not limited to Harakat al-Shabaab al-Mujaahidiin (‘Al-Shabaab’)”.

Al-Shabaab is one of East Africa’s most deadly terrorist groups, connected to at least 120 deaths in Somalia since the beginning of 2016. Last month, the al-Qaeda affiliate claimed responsibility for an explosion that blew a hole in the fuselage of an Airbus A321. On Monday, the U.S. Pentagon claimed it had killed at least 150 al-Shabaab fighters in a heavy bombing attack using drones and manned aircraft.

A Daalio Airlines plane minutes after it made an emergency landing on 2 February in Mogadishu following a bomb blast. Al-Shabaab claimed responsibility for the attack. Mohamed Abdiwahab / AFP / Getty Images

UN investigators have requested information from authorities in Norway, including banking records and any intelligence on Khaire’s relationships to these groups. The Soma executive is a Norwegian national and a former regional director of the Norwegian Refugee Council, a large Oslo-based NGO with operations in East Africa.

In a statement to BuzzFeed News, Soma "strenuously denied” any wrongdoing and said it was cooperating fully with the SFO.

The company said it had no knowledge of the UN’s inquiries to the Norwegian and British governments and was unaware of any investigation into possible extremist links involving Khaire. After being contacted by a member of the UN investigation team in January, the company added that "it was our understanding that enquiries may be pursued with the US and Norwegian authorities”.

The statement continued: "Mr Khaire does not have any links with East African extremist groups including Al Shabaab. For the avoidance of doubt, he has no link or affiliation to any known terrorist organisation or member of a terrorist organisation.

On the SFO inquiry, the statement said: "Soma is confident that there is no basis to the allegation and it is co-operating fully with the SFO to answer its queries. No charges have been laid against the company or any individual. Soma has always conducted its activities in a completely lawful and ethical manner and expects this matter to be resolved in the near future.”"Any direct or implied reference to either Mr Khaire or Soma (by association) having any, or any possible, connection to a terrorist organisation would be highly damaging and defamatory.

Khaire, the statement added, "repeats that he has not knowingly ever been in contact with any terror group or any member of such a group. If he has had contact with any person who may have such affiliations, any suggestion that this was done knowingly or nefariously is untrue and would be highly defamatory.”