A 52-year-old man, arrested ahead of next week's local elections in Birmingham, was a Liberal Democrat candidate, his party has confirmed.
Mohammed Khan, of Hob Moor Road, Bordesley Green, Birmingham, was arrested on Thursday afternoon on suspicion of conspiracy to defraud.
His wife was arrested a day earlier, also for conspiracy to defraud. Both have been bailed by police.
Mr Khan would still stand in the elections, the Lib Dem group said.
Mrs Khan was arrested following the discovery of a quantity of postal voting forms at an address in Ronald Road, also in Bordesley Green.
West Midlands Police and the Electoral Commission are keen to avoid the vote-rigging scandals which marred the city's 2004 local elections.
The representatives for Aston and Bordesley Green were forced to step down after the Electoral Commissioner found evidence of postal ballot abuse.
One councillor was later cleared, on appeal, of corrupt practices.