Jail sentences of between six months and three years will be imposed on those proven to have voted more than once in the constitution referendum, Administrative Development Minister Hany Mahmoud announced on Thursday.

The announcement comes after interim President Adly Mansour amended the political rights law on Monday to allow citizens to vote in the referendum at polling stations not affiliated to the address listed on their national identification card if they live in a different governorate.

Citizens who reside in their hometown must vote at their registered polling station, Mahmoud added.

He said that over 200 polling stations have been allocated for those residing outside their home governorates.

The move is expected to increase turnout at the 14-15 January referendum, but has raised fears that some voters might cast more than one ballot.

A large percentage of voters live far from their registered addresses, which prevented many from taking part in previous polls.

The high electoral committee announced that a computerised database would be used to curb vote-duplication in the referendum.

In parliamentary polls in 2011, as well as the presidential election and constitution referendum in 2012, voters had to vote at specific polling stations linked to the address mentioned on their national identity card or passport.

The forthcoming vote will be the first landmark in a transition roadmap drawn up after the army overthrew Islamist president Mohamed Morsi in July amid massive protests against his rule.

Parliamentary and presidential elections are scheduled to follow by mid-2014.