Panther's Claw saw UK troops' highest monthly death toll since 2001
Polling centres in part of Afghanistan where UK troops died trying to create a secure election environment face audits and recounts after alleged fraud.
Three of the four centres in Babaji, Helmand province, are being examined.
Ten UK soldiers were killed in Babaji district as Operation Panther's Claw fought the Taliban ahead of elections.
Afghanistan's election complaints commission is excluding votes from more than 70 polling stations where it has found evidence of fraud.
Thousand of votes were recorded from the Babaji stations under suspicion.
But one election observer has told the BBC that no more than 15 people voted throughout the day at the centre where he was based.
Reports that about 150 people voted in Babaji district, out of an eligible population of 55,000, have not been disputed by officials in Afghanistan.
Foreign Secretary David Miliband has said the UK "will not be party to any whitewash" over the presidential election.
He has made a point of not categorising the election as "free and fair", but said he still believed "the new government can be a legitimate and credible expression of the will of the Afghan people".
He told BBC Breakfast: "Significant numbers of people didn't come out because they were frightened but equally millions did vote and we need to make sure that the courage they showed and the courage that our forces have shown is actually matched by a determination to get the real result.
"If President [Hamid] Karzai won then he should be the president; there's then big responsibilities on him to reach out right across the Afghan political spectrum.
"But obviously if he didn't get the 50% in the first round then there has to be a second round."
Mr Miliband added: "For us in Britain, the absolute key is that the new government is, first, credible, and also has a clear programme in the three areas that will decide the future of Afghanistan: its security forces, its ability to achieve political reconciliation and its ability to build the economy, above all in agriculture."
On Thursday, US envoy to Afghanistan Richard Holbrooke said the independent election commission should be allowed to complete its vote counting before people made judgements about the poll.
Nearly all the votes being excluded by the election complaints commission, from polling stations in the south and east, were cast in favour of Mr Karzai.
The commission has also ordered recounts at a number of other polling stations.
The investigation could take months, plunging Afghanistan into political uncertainty.
Mr Karzai's supporters say many of the complaints are politically motivated.
His main challenger, Dr Abdullah Abdullah, has accused the election commission of rigging the count to favour Mr Karzai.