The Tewhid mosque was one of two closed down after authorities found gunman Kujtim Fejzulai, who killed four people in central Vienna in November, frequented them.
Austria’s main Islamic body, the Islamic Religious Community of Austria (IGGOe), has agreed to let the mosque reopen after an internal probe, the group’s spokeswoman Valerie Mussa told AFP.
Police said last month they had to withdraw the closure order after they found Fejzulai just visited the place together with others who held radical beliefs, but none of them were involved with the association running the mosque.
“As it now turns out, the claim brought to us that there was an imminent danger cannot be substantiated,” IGGOe president Uemit Vural said in a statement.
Closing a place of worship should “in no case be arbitrary”, the statement added.
However Susanne Raab, the minister in charge of religious matters under Austria’s conservative government, called the IGGOe’s decision to allow the Tewhid mosque to reopen “incomprehensible and irresponsible”.
The shooting was Austria’s first major attack in decades and its first blamed on a jihadist. Police killed Fejzulai, a 20-year-old convicted Islamic State sympathiser.
Prosecutors say around 10 suspects are still in custody over the attack but that as yet no charges have been pressed.
A man was arrested last week as investigators look into whether he was an active accomplice or simply knew of Fejzulai’s plans.