By Daniel Flynn and Diadie Ba
DAKAR (Reuters) - The arrest of the former president's son on corruption charges in Senegal should be taken as a sign that the age of impunity in public life is over, Justice Minister Aminata Toure said on Tuesday.
Karim Wade, the most powerful figure in his father Abdoulaye Wade's 2000-2012 government, was arrested last week on suspicion of amassing up to $1.4 billion (918.4 million pounds) in assets via a network of shady holding companies.
Prosecutors are investigating graft allegations against at least four other former ministers.
The opposition alleges that the inquiry was little more than a political witch-hunt.
But Toure disagreed and said President Macky Sall was making good on promises to tackle widespread corruption in the poor West African country after he won power a year ago.
"There's an element of setting an example in all this. People must understand that the time when one could pillage public funds is gone," Toure told Reuters in an interview.
"From now that's how it is. Even members of this government will be held accountable."
The aim was to change the culture of public life and prevent bribe-taking throughout the administration, Toure said.
Senegal, a former French colony, is the only country in West Africa not to have suffered a military coup since independence, but its political stability was tested by Wade's efforts to win a third term last year.
It ranked as one of the cleanest countries in West Africa in graft watchdog Transparency International's Corruptions Perceptions index for 2012, coming 95th out of 174 countries surveyed, behind only Ghana in the region.
On Tuesday, hundreds of Wade's supporters marched in central Dakar to protest his detention. "Down with the fascist government," read one sign.
"It's normal in a democracy that there are differences of opinion and people have the right to protest ... but I have also received many long letters of support," Toure said.
Karim Wade dominated his father's government, simultaneously occupying four key ministries with a total budget equivalent to one-third of state expenditure.
Prosecutors accuse him of taking stakes in large sectors of the economy via a web of offshore companies, notably firms involved in managing Dakar port and providing airport services.
"The fight against corruption should be good for economic growth," Toure said. "It will reassure investors it is no longer the survival of the fittest."
Wade's arrest comes amid a flurry of judicial activity in Senegal, led by Toure, as the country also presses ahead with the long-delayed trial of former Chadian dictator Hissene Habre, accused of crimes against humanity during his 1982-1990 rule.
Habre has lived in Senegal for the last 22 years but plans for his prosecution stalled under Wade's government.
"If we can serve as an example to the rest of Africa, we would be happy," she said.
(editing by Mike Collett-White)