The Swiss prosecutor's office said on Friday former banker Rudolf Elmer would be detained over the weekend after police questioned him this week over possible fresh breaches of Swiss bank law.

A judge will announce on Monday whether Elmer will then be held for longer on remand, the prosecutor's office said.

Elmer was taken into custody by police on Wednesday evening after he handed over computer discs to WikiLeaks earlier this week. Elmer indicated the CDs contained details of as many as 2,000 offshore bank accounts.