The idea behind the appointment was to provide spiritual guidance for the couple of thousand children with a Muslim background who regularly visit the youth centre.
But when foreign ministry officials discovered internet postings which portrayed Al Tawalbeh in a negative light, they reported the postings to the Stockholm police, who handed the matter over to Säpo.
"They said that they are concerned for my welfare and that they are taking the matter seriously," Al Tawalbeh told local newspaper Helsingborgs Dagbladet.
The texts, which are written in Arabic and have found their way into established Arab newspapers, describe Al Tawalbeh as an apostate, someone who has left the true faith.
According to Al Tawalbeh, the author is Mahmoud Aldebe, a prominent Swedish Muslim who caused headlines in 2006 when he was advocating Sharia laws in Sweden.
“He claims that most people think that I poison the true Muslim faith, that I will try to turn Muslim youngsters into Christians and that I advocate women's rights,” Al Tawalbeh told HD.
Al Tawalbeh said he is used to being criticised but that this time it is more serious.
“Family and friends are worried and have contacted me to find out what is going on,” he said.
The police confirmed that Säpo has been in contact with Al Tawalbeh but told HD that it is too early to say how serious a threat he is facing.
The Church of Sweden has also been criticised for the appointment of Al Tawalbeh.
On Sunday two Swedish female priests wrote an article in the Svenska Dagbladet (SvD) newspaper in which they questioned the appointment of an imam by a foundation run by the Church of Sweden.
Annika Borg and Johanna Andersson argued in the article that a prerequisite of being employed by the Church of Sweden had so far been to share the same core values, whether employed as a priest or as a janitor.
“It is our opinion that the appointment of an imam is unfortunate. It is a step taken too rashly and without proper consideration,” they wrote in SvD.
Despite the possible threat, Al Tawalbeh is eager to be getting on with his new job and his first prayers are scheduled to take place at Fryshuset in Stockholm this coming Friday.