Dar es Salaam - President John Magufuli fired Tanzania's mines minister on Wednesday after a government report found minerals exports had been understated, causing a loss in tax revenue.Mining minister Sospeter Muhongo, a friend and ally of the president, was dismissed along with the head of the Tanzania Minerals Audit Agency, Dominic Rwekaza."The minister is my friend and I like him very much but I will not forgive him for this," Magufuli said in a televised address after receiving the report on Wednesday. "I want him to reconsider his position and I am advising him to step down."A later statement issued by the presidency confirmed that Muhongo had been fired. "The dismissal takes effect this Wednesday 24 May," the statement said.Wednesday's report found that companies exporting raw mineral sands understated the nature and quantity of precious metals in their containers and so avoided paying taxes.In March the president ordered a ban on the export of raw minerals hoping instead to develop a domestic processing sector with smelters and refineries to boost the economy.Tanzania is one of Africa's top gold producers, and also exports copper, nickel, silver and precious stones.Muhongo is the second minister fired in three months by Magufuli, who swept to power in 2015 as a no-nonsense, corruption-busting man of the people but has drawn criticism for an authoritarian streak.Information minister Nape Nnauye was sacked for criticising an ally of Magufuli's who had stormed into a television station accompanied by armed men demanding they air a certain video.