Mr Kaunda, originally charged with treason, walked free from the court after the state withdrew its case.

He described the decision as great.

Big trial expected

Kenneth Kaunda was due to face the charges relating to an attempted coup.

He was one of 81 defendants charged with either directly participating in the coup attempt or concealing knowledge of it from the Zambian authorities.

The hearing, with more than 150 witnesses listed, was set to be the biggest treason trial in Zambia's history.

Lawyers acting for Mr Kaunda had maintained hopes throughout the legal process that the case against him would be dropped.

Coup crushed

Kenneth Kaunda was charged with knowing about preparations for a military coup last October but failing to inform the Zambian authorities.

The badly organised coup attempt was quickly crushed by loyal forces of the Zambian Army.

In the aftermath, the government arrested scores of opposition activists. Mr Kaunda was detained in December and subsequently moved from jail to house-arrest.

Opposition gaining support

Government opponents regarded his trial as a crude attempt to silence opposition political leaders at a time when they are gaining increasing popular support.

High unemployment and economic stagnation in Zambia has led to widespread disillusion among the voting public who ended Mr Kaunda's 27 years in power at multi-party elections in 1991.