Sir Mark Thatcher's decision to plead guilty to unwittingly helping an alleged African coup plot is the latest twist in one of the more bizarre and murky tales in the continent's history of power struggles involving natural resources.
Sir Mark is expected to tell a South African court on Thursday that he helped finance the hire of a military helicopter to be used by alleged mercenaries but knew nothing about their alleged plan to overthrow the repressive government of the tiny but oil-rich western African state of Equatorial Guinea.
Police allege Sir Mark provided more than $270,000 (£145,000) for the alleged conspiracy to overthrow President Teodoro Obiang Nguema. The alleged coup has been an embarrassment to South Africa, which condemns mercenary activity.
The alleged plot has highlighted the opaque world of African oil politics, the opportunists inhabiting it and the abusive and secretive nature of an oil-rich country where US oil multinationals pump more than 300,000 barrels a day of crude.
The story began after more than 80 alleged mercenaries were arrested in March in Malabo, Equatorial Guinea's capital, and at the airport in Harare, Zimbabwe's capital.
Equatorial Guinea's government claimed the alleged plot was an international conspiracy, backed by members of the British establishment including Sir Mark, to install Severo Moto, an opposition leader in exile in Spain.
Sir Mark was arrested in South Africa in August on two charges of violating a law that prohibits mercenary activity and unauthorised foreign military aid.
Sir Mark's name was linked to the alleged plot after Simon Mann, a former British special forces soldier accused of co-leading the coup operation, smuggled a letter out of prison in Zimbabwe calling for help from "Smelly" and "Scratcher".
"Scratcher" looked like a nickname for Sir Mark, who has acknowledged his friendship with Mr Mann but has refused to talk about the affair. The case has also drawn in the UK government, which is accused by its Equatoguinean counterpart of failing to pass on a tip-off about the alleged plot.
Britain's Foreign Office has said it became aware of rumours of a possible coup in January last year, but was "sceptical" about the reports because of previous coup rumours that proved unfounded.
The process leading up to Sir Mark's plea on Wednesday began after Mr Obiang named him in August in a French magazine interview as a backer of the alleged coup plot, adding that an un-named minister in one of Mrs Thatcher's governments had also been involved.
Sir Mark's may not be the last high-profile name to suffer in connection with an affair that is still far from clear and has damaged further the already controversial reputations of both the Equatorial Guinea government and those accused of trying to overthrow it.
Wednesday's development will generate headlines and be of interest to historians, but, given Lady Thatcher's absence from public life, will have limited political fallout in the UK.
The Equatorial Guinea government is widely accused of making up previous "coup attempts" as an excuse to persecute political opponents, dozens of whom were held ahead of the 2002 presidential elections that Mr Obiang won with more than 97 per cent of the vote.
(12 January 2005)