The centre's administrator was brutally beaten two weeks ago after issuing trespass orders to a Salafist imam and some of his supporters, and spent 10 days in hospital with fractures and eye injuries.
Mr Frost said he was assaulted twice as he was handing out six trespass orders to people causing trouble at the Blockhouse Bay Rd mosque on Sunday.
"A man spat at me and another struck me, and there was no reply from me," he said.
One of the men then started shaking and chanting in Arabic, and Mr Frost heard some others saying the man was declaring a jihad.
"My understanding of jihad is that it is a religious assassination notice, I take this threat really seriously ... and I'll be acutely aware of the vulnerability of up to seven children in my home," said Mr Frost.
"It appears that these [people] are radical fundamentalists ... to actually put a jihad on a New Zealand citizen trying to enforce New Zealand law is ludicrous."
Police Superintendent Wally Haumaha told the Herald last Friday when he visited the mosque that police were investigating one assault complaint and would "certainly be investigating" any others made.
Dr Zain Ali, head of Islamic research at the University of Auckland, said Mr Frost should be concerned with the threat.
"If the jihad had been made as a genuine declaration it can include a number of things including the declaration of war, and I think the security staff is right to be concerned," said Dr Ali.
"Even if it was said in the heat of the moment, it really means that emotions have taken over and ... people are appealing to tradition to justify what they are doing, and this can include physical violence."
But Mr Mohammed Selim, whose friends were among those who had been served with trespass orders, denied they were extremists or violent and believed it was wrong to stop them worshipping at the centre.
"We signed a contract when we came to this country that it is a free country, free to practise our worship and nobody will stop you," said Mr Selim, originally from Egypt. "Suddenly the problems start to happen and everybody get trespassed, what law did we break or what kind of violence did we make?"
Another worshipper, Farouq Ismael, said he was planning a protest because money from members' donations to the mosque was being used by the association to pay for the security and fences.
Two Islamic factions have been embroiled in a battle for control at the mosque for over two years.
