Ballot riggers may have deliberately hidden votes from the 2004 Birmingham City Council elections as part of a sophisticated campaign of fraud, a former councillor has claimed.
A council investigation sparked by the discovery of a box of uncounted votes in the elections office ten months after polling day is expected to blame incompetence rather than intent.
But a former Tory councillor, who lost his Kings Norton seat by one vote, believes there may be a more sinister explanation to the "forgotten" ballot papers.
Tony Ward claimed someone could have exchanged the 255 genuine votes for a larger number of forged ballots.
But Mr Ward said it would be impossible to prove his theory because of the council's "cavalier" attitude towards the supervision of postal voting.
The 255 ballot slips were seized by the West Midlands Police fraud squad in April.
The discovery of the box of votes in a locked cupboard led to the suspension of council elections officer John Owen and a member of his staff. Both remain suspended on full pay pending a council disciplinary inquiry.
Mr Ward pointed out that the box contained 176 " envelope 4's" - which are available at each of Birmingham's 520 polling stations. Presiding officers must place any postal votes handed in at the polling stations inside the envelope.
He added: "What has not been established is whether these envelopes were simply omitted from the count, due to insufficient attention to detail by the elections office staff, or whether they had been substituted by other envelopes filled with ballot papers created in a vote-rigging factory.
"What has been established is that the absence of the envelope 4's was not picked up. Therefore, whatever audit trail was in place was not robust enough to pick up the discrepancy."
Mr Ward criticised council chief executive Lin Homer, who said that in only two out of 16 wards could the uncounted votes have made a difference to the election result.
He added: "The system on which she is relying failed to pick up 171 missing envelopes. Each of those may have been removed from the system and replaced by other envelopes containing a large number of votes.
"Can any faith be placed in the results of any ward in the Birmingham local elections of 2004?"
A council scrutiny committee is due to quiz Mrs Homer about the arrangements for the 2004 council elections.