The Jewish Labour Movement has called in the police to investigate its finances, members were told late on Wednesday night.
In an email circular, it said it had taken steps over the past week to ensure its financial governance met "the highest standards" expected by members and instigated an external review of its accounting and procedures, as well as taking legal advice.
It said in order "to ensure full transparency, openness and to protect the integrity of the movement, we have referred certain internal financial matters to the police for investigation".
But it said it would "not be appropriate for us to make any further comment" at the present time.
