The Swedish Security Service still think he was alone.
Via the Local:
Taimour Abdulwahab called a mobile telephone in Iraq the same day that he blew himself up in Stockholm, and received 60,000 kronor ($8,800) from backers in Scotland, according to British prosecutors.
The UK authorities are investigating 31-year-old Nasserdine Menni, who is suspected of financing the attack and was arrested in Scotland in March.
During the investigation it has emerged that Abdulwahab rang a mobile telephone in Iraq the same day he blew himself up. He also received a call from a mobile telephone in Iraq and then called Menni repeatedly.(source)