Afghan election officials found themselves probing a cold case Tuesday, after a top presidential contender cried foul when two police officers slept in an election data centre - supposedly to escape chilly weather.

The strange incident occurred Sunday night, when the two officers were invited into Kabul's election data centre, which is supposed to be locked down, where results from the September 28 first round of presidential polls are being collated. 

According to Independent Election Commission (IEC) official Aurangzeb, who only goes by one name, the officers were allowed into the sealed building to "spend the night in the corridor because of the cold weather outside."

But the case underscores high emotions around the election.

The team of Afghanistan's Chief Executive Abdullah Abdullah, who is President Ashraf Ghani's main rival, said the officers had conducted nothing less than an "organised attack in collusion with (Ghani's) team to change the outcome of the election".

IEC chairwoman Hawa Alam Nuristani said the incident would be investigated and "the perpetrators dealt with". 

Aurangzeb said "a mistake happened out of emotion and ignorance, but it should not be exaggerated."

The incident generated some online ridicule in Afghanistan. 

"Why would someone break the seal and enter the data centre in the middle of the night to keep warm? Is it a data centre or a heating centre?" one Facebook user wrote. 

Initial election results were supposed to have been released Saturday but were postponed, and previous ballots have been mired in fraud allegations and violence.

Abdullah claimed victory just two days after this year's vote, in a move that international and local observers panned as premature. His team later alleged "systemic fraud".