The Singapore government's Commercial Affairs Department said yesterday that there were "insufficient grounds" to bring charges, bringing its 15-month investigation into Barings, now owned by Dutch financial group ING, to a close.
Mr Bax was unavailable for comment. George Lim, the lawyer representing Mr Jones, said: "He [Jones] has always asserted his innocence."
Two other people investigated who will not face criminal proceedings are Edmund Wong, a director of Contact Software Engineering, which supplied Barings' computerised settlement system, and Daniel Argyropoulos, a close friend of the jailed Leeson and a trader with FCT (Singapore).
There has been strong speculation in Singapore that Mr Argyropoulos might be charged with helping Leeson in his unauthorised trades.
"After careful consideration of all the evidence, the Commercial Affairs Department has recommended to the attorney-general that there are insufficient grounds to bring criminal charges against them," a spokesman said. The findings have been accepted by Chan Sek Keong, the attorney-general.
The investigation began immediately after the Barings collapse, which was caused by Leeson's unauthorised trading in Asian futures and options that plunged the bank pounds 860m into the red.
The inquiry intensified last autumn following a report from inspectors in Singapore that partly blamed Barings managers for the collapse.
The report accused senior managers at Barings with covering up losses on some of the trades made by Leeson, who is serving six and a half years in jail, and preventing internal auditors from probing them.
It specifically mentioned Peter Norris, head of investment banking in London, and Mr Bax, who had his passport confiscated by the Singapore authorities.
The Barings affair has yet to come to a complete close, however. Price Waterhouse, the liquidators of Baring Futures (Singapore), is suing two leading accounting firms for pounds 460m each, alleging negligence prior to the collapse of the bank.
The accounting firms Coopers & Lybrand Singapore and Deloitte & Touche said last week they would fight the allegations by BFS liquidators Price Waterhouse.