One of the men suspected of carrying out the Westgate mall attack in Kenya has been identified as a Norwegian citizen.
At least 67 people died in the attack in Nairobi in September, which the al-Qaeda linked group al-Shabab says it carried out.
Hassan Abdi Dhuhulow, 23, is one of four gunmen seen on security camera footage inside the mall.
Until now, little was known about the four attackers who were seen on CCTV footage during the siege of Westgate. Investigators knew them by the colour of their clothes, dubbing them 'black shirt', 'white shirt', 'blue shirt' and 'pink shirt'.
But sources close to the investigation in Kenya and Norway told the BBC they believe the man identified as 'black shirt' is Hassan Abdi Dhuhulow.
Mr Dhuhulow fled Somalia with his family in 1999 for Norway and returned to Mogadishu 10 years later. Since then, a family member said he had been in only sporadic contact.
Last week Norway's intelligence agency, the PST, said it had sent officers to Kenya to verify reports that a Norwegian citizen had been involved in the assault on the shopping centre, which began on Saturday 21 September and lasted four days.
It is unclear how many militants were involved in the attack. Police had initially estimated that there were 10-15 attackers inside the complex, but the CCTV footage which has so far been released by the Kenyan authorities shows only four men.
Forensic investigators are still combing through the rubble of Westgate - no bodies have yet been identified and it is not known whether the attackers are alive or dead.
