Tanzania's main airport benefited from the deal

President Jakaya Kikwete said officials found guilty of taking bribes during the deal would be punished.

The UK'S Serious Fraud Office is investigating the sale of the air traffic control system by BAE Systems five years ago.

There are allegations that a middleman was paid $12m to win the order.

"We did not procure the radar from the streets. We shall lodge formal request for refund from the British government upon proof that BAE inflated the price of the radar to squeeze extra money out of our poor country," Mr Kikwete told reporters at State House in Dar es Salaam.

'Ashamed'

The BBC's John Ngahyoma in Tanzania says government officials insist that all procurement procedures were followed during the purchase of the radar system.

President Kikwete maintains that Tanzania had the right to buy the air traffic control system and Britain should be ashamed if British businessmen took advantage of the transaction to earn illegal income, reports the AFP news agency.

BAE says it is co-operating fully with the investigations but has strongly denied operating a secret slush fund to sweeten deals.

At the time of the sale, the serving UK International Development Secretary Clare Short criticised the sale of such an expensive system.

"I believe that all the parties involved in this deal should be deeply ashamed," Ms Short, now an independent MP, said in a Commons debate on Tuesday night.

She said the deal was "useless and hostile to the interests of Tanzania"

Opposition politicians in Tanzania have been calling on the government to undertake independent investigations on the matter.