Police have arrested two men in the northern English city of Bradford as part of an inquiry into postal ballot fraud.
West Yorkshire police said they arrested a 51-year-old man today after detaining a 38-year-old man yesterday and that more arrests were anticipated.
Earlier this month, an election commissioner described postal voting as an "open invitation to fraud" after an inquiry into a local election in Birmingham.
Bradford Council had referred over 100 applications for postal ballots for tomorrow's election to police for investigation.
Acting returning officer for Bradford district Philip Robinson said security checks had been made on all postal vote requests.
"We check every single one. We are working very closely with police to stop ballot fraud taking place," he told the Yorkshire Postnewspaper.
The deadline to apply for a postal ballot expired yesterday with early indications showing that 6 million voters across Britain - 15 percent of the total - have applied to take part in the election by post.
In the 2001 election, there were just 1.7 million applications. The extra take-up has been welcomed by the government, which introduced on-demand postal voting in 2001 to boost flagging turnout, but it has raised fears of vote-rigging.