A new police and crime commissioner (PCC) election will cost more than £1m and will be funded by central government, Wiltshire Council has said.
Conservative candidate Jonathon Seed gained the most votes in the Wiltshire PCC on Monday, but due to a historical conviction is ineligible to serve.
Returning officer Terence Herbert is now seeking legal advice and will set out the process for a fresh election.
The BBC has asked Wiltshire Council and the Conservative Party for comment.
Other election candidates suggest a new election could cost in the region of £1.4m to local taxpayers, with some calling for the Conservative party to pay the costs.
Mr Herbert said "Given this unprecedented situation and given the circumstances, I will be seeking legal advice on the next steps and at that point I will be able to make any statements necessary about the position.
"If the post of the PCC is vacant, if someone is disqualified or does not sign the declaration, then the post will be defined as vacant and an election will be called."
Wiltshire Police said Mr Herbert was working with the PCC's office and policing would be unaffected by this event.
A spokesperson for the police force said: "It is now a matter for the Police Area Returning Officer (PARO) to set out what the process will be in these unique circumstances."
The Office for the Police and Crime Commissioner in Wiltshire said there was legislation in place for this eventuality and due process would be followed.
It also confirmed the current PCC Conservative Angus Macpherson would remain in post until Thursday.
When all the first preferences were counted, Mr Seed had 84,885 votes, nearly 50,000 more than second-placed Liberal Democrat candidate Liz Webster but not enough to avoid the vote going to second preferences.
With second preference votes counted, Mr Seed gained 100,003 and second placed Liberal Democrat candidate, Liz Webster, polled 58,074 votes.
Other first-preference votes in the Swindon and Wiltshire PCC election were; Liz Webster (Liberal Democrat) 35,013, Junab Ali (Labour) 34,147 votes, Mike Rees (independent) 31,722, Brig Oubridge (Green Party) 16,606 and Julian Malins QC (Reform UK) 4,348.