Birmingham MP Andrew Mitchell has spoken out after he came under fire for his involvement with a cocoa magnate.

The Conservative MP for Sutton Coldfield was targeted by a Labour MP who complained to the Commons sleaze watchdog after it emerged Mr Mitchell had supported attempts to lift a trading ban imposed by the government of Ghana on UK firm Armajaro Holdings.

Speaking to the Birmingham Post, he denied any claims of wrongdoing and vowed he would not be distracted from his work in international development or for his local constituents.

Armajaro Holdings gave £40,000 to Mr Mitchell’s parliamentary office to support his work as shadow International Development Secretary while the Conservatives were in opposition.

The firm’s co-founder Anthony Ward, who wrote to Mr Mitchell asking for help, became known as Chocfinger after cornering a huge chunk of the world chocolate market by buying 241,000 tons of cocoa beans. But the parliamentary standards commissioner John Lyon announced earlier this week he will not be holding an inquiry.

Mr Mitchell said: “The letter from Armajaro was dealt with in accordance with normal ministerial procedures.

“It was immediately made clear that the Conservative Party had previously received donations from the company and the matter was referred to the Foreign Office through the normal channels.”

Mr Mitchell said he was getting on with his job on behalf of his constituents and had received a large number of supportive letters and e-mails since the story was reported in the Sunday Times.

The MP received funding from a range of donors, including Armajaro, to help pay his office costs in opposition, including funding travel to the developing nations.

An internal Department for International Development memo published under the Freedom of Information Act shows that he spoke on July 6 to Nick Westcott, the British High Commissioner in Ghana, about Armajaro.

The firm had been banned from doing business in Ghana over claims that one of its contractors had been smuggling cocoa.

Mr Mitchell began the conversation by declaring an interest stating that Armajaro had funded Conservative party development efforts, according to the memo.

Mr Westcott said he had already raised the issue with Ghana and would continue to press Armajaro’s case, as he would with any other UK company in a similar position.

The pair agreed that the letter from Armajaro should be passed to the Foreign Office to be answered.

When the story broke, Labour MP John Mann referred the minister’s case to the standards commissioner, saying it “raises serious questions to answer about the Secretary of State’s conduct”.

This led to speculation that Mr Mitchell could face a formal inquiry, but the commissioner almost immediately ruled that there were no grounds to hold an investigation.

Mr Ward dramatically cornered a huge chunk of the world’s cocoa supply earlier this year when his business bought enough beans to manufacture 5.3?billion quarter-pound chocolate bars.

There was speculation he could use his holding to force manufacturers to raise the price of some of Britain’s most popular chocolate.

The move was the largest single cocoa purchase for 14 years.