OSLO, Norway – Norway’s domestic intelligence service tried to prevent one of the suspected gunmen in the Nairobi mall attack from joining Somali militants more than three years ago, but failed to talk him out of it, the agency’s chief said in an interview Wednesday.

The man has been identified in Kenya as Hassan Abdi Dhuhulow, a 23-year-old Somalia native whose family moved to Norway in 1999. Norwegian authorities have still not named him, and had previously not said whether they knew of him before the four-day siege of the Westgate mall that killed nearly 70 people in the Kenyan capital.

But Marie Benedicte Bjoernland, the head of Norwegian security service PST, told The Associated Press that the Norwegian suspect was well known to her agency and that it even tried to dissuade him from becoming a jihadist.

“We had several talks with him … before he left Norway more than three years ago,” Bjoernland said at PST’s headquarters in Oslo. “Obviously we didn’t succeed, but there was quite an effort put into the preventive side of this.”

Bjoernland declined to give details of the conversations, and said the Norwegian “most likely” died in the attack, though PST investigators haven’t confirmed that. The Kenyan government said Sunday it believes it has recovered the remains of the four gunmen seen in CCTV footage carrying out the attack.

Security camera images showed what appeared to be Dhuhulow and three other gunmen firing coldly on shoppers as they made their way along store aisles after storming the upscale mall.

The Somali Islamic extremist group al-Shabab claimed responsibility, saying the September attack was retribution for Kenya’s military involvement in Somalia.

Dhuhulow’s sister told AP last week that her brother went to the Somali capital of Mogadishu for a three-month visit in 2009, then moved to Somalia for good in March of the following year. She said she didn’t believe he was among the gunmen seen in the footage.