South African private bank FirstRand has approached the South African Revenue Service to explain the working of an offshore tax scheme run by its former private banking arm, Ansbacher Trust, following allegations in court that the scheme was illegal.

Selwyn Shapiro, legal advisor to tax consultant Barry Spitz, was approached by SARS last week to hand over all documents relating to a court case between Mr Spitz and FirstRand. These contained the financial records of Ansbacher Trust and the so-called Duisberg scheme.

Mr Spitz, in a civil case to recover ZAR2.3 million ($330,000) he claims he is owed by the bank for consultancy work, alleges that his services were terminated earlier than planned because he had told FirstRand that the Duisberg scheme was "artificial and vulnerable to attack".

In spite of FirstRand's continued insistence that the scheme was legal and above board, the bank has expressed concern over the negative publicity the case has attracted.

A FirstRand spokeswoman said: "FirstRand has requested a meeting with SARS to give them a proper briefing and proper context to the scheme. We want them to understand exactly how it operated."