West Australian mining companies with operations in Africa have had A$3.6 billion ($3.7 billion) wiped from their value in the past year.
Falling commodity prices, the Ebola epidemic, labour issues and geopolitical tensions have combined to scare off investors, and those remaining have seen their shares almost halve in value.
A Deloitte Australia report shows the combined market value of publicly listed West Australian companies with operations in Africa dropped by A$3.6 billion, or 47 per cent, in 2014, to A$4 billion.
Weaker demand from the Chinese manufacturing sector, a strengthening US dollar and oversupply of some of the major commodities had a major impact on Africa, said Deloitte clients and markets partner for Western Australia Tim Richards.
"Coupled with the Ebola outbreak in West Africa, as well as challenges relating to industrial relations and geopolitical tensions, 2014 was a challenging year for many companies and has highlighted the changing nature of investment into Africa," he said.
Merger and acquisition activity was responsible for nine African-focused companies exiting the sharemarket, which contributed to A$2 billion of the fall in net worth of the companies.
But the report found the sector still has potential, with Australian investment in the oil and gas sector in Africa increasing over the past few years.
The release of the Deloitte figures coincides with the start of Africa's largest mining conference, Mining Indaba, in Cape Town yesterday.
Fewer delegates are expected this year and many West Australian mining executives are staying away from the event.
Australia-Africa Mining Industry Group chief executive Trish O'Reilly said Indaba organisers had been offering discounts to stimulate interest in the conference.
At the peak of investment about 18 months ago, around 230 Australian companies were active in 42 African countries.
Since then many junior explorers have shelved plans, particularly in Ebola-affected countries.
West Australian premier Colin Barnett delivered a keynote speech at the 2014 Indaba conference but he will not be attending this year.