Mr Crook joined Henry Ansbacher three years ago as a senior dealer in South African government bonds and gold shares. Yesterday he was expelled from the register of the Securities and Futures Authority (SFA), which will bar him from trading in the UK. He has also been ordered to pay the SFA costs of pounds 8,500.
An SFA tribunal found that Mr Crook had "consistently and repeatedly lied or resorted to half-truths" during interviews with the regulator about his bank accounts.
Ansbacher is owned by South Africa's First National Bank of Southern Africa and has been reprimanded, fined pounds 20,000 and required to pay costs of pounds 5,400, the SFA said. A spokesman for Ansbacher said: "No comment."
The SFA has handed details of Mr Crook's case to the City of London Police. They were unable yesterday to confirm whether they were investigating Mr Crook.
A spokesman for the SFA said: "I am not saying that our case against Mr Crook revolved around intent to permanently deprive his employer of the $70,000, but the circumstances of the case automatically put it into the `notify police' category."
Mr Crook, a South African national, joined Ansbacher in April 1994. The following August, while the manager in charge of deal settlements was on holiday, Mr Crook made a payment of $70,000 by pretending that these were funds needed by a new trading account opened by Ansbacher with another firm.
The SFA says: "In fact no such account existed, and the payment was really an unauthorised transfer of funds to an associate of Mr Crook in Zimbabwe."
When the settlements manager returned from holiday he realised that this payment had not been properly authorised.
The SFA was told about the deal by the bank in June 1995, by which time Mr Crook had been suspended. He had also repaid the $70,000 by borrowing the money personally. He was later sacked for "gross misconduct".