Nuttall denies making a false declaration by registering his home address to a Stoke property.
Ukip leader Paul Nuttall is facing a police investigation over claims he misled voters by registering his home address to a property in Stoke, where he is fighting a by-election against Labour.
The Bootle-born MEP, who represents the North West of England in the EU Parliament, has said the listing on his nomination papers is not a "false declaration".
"A candidate being attacked for being prepared to move to his constituency must be a first," he added. The probe comes after Channel 4's Michael Crick visited the home and found nobody inside.
"People are in the process of moving us in," he told the veteran reporter.
The Electoral Commission's guidance to prospective parliamentary candidates states that home addresses "must be your current home address".
A spokesperson for Staffordshire Police said: "We have received a report of an allegation of election fraud relating to the Stoke Central by-election on Thursday 23 February 2017. Officers will be investigating the circumstances."
The 23 February by-election was triggered after former Stoke-on-Trent Central MP Tristram Hunt quit the House of Commons to become the director of London's Victoria and Albert Museum in January.
Labour have selected Gareth Snell to defend Hunt's majority of more than 5,000. But Nuttall is hoping to win over the 69% of Stoke residents who backed a Brexit at the EU referendum in June.
The Stoke-on-Trent Central by-election is being held on the same day as the Copeland by-election. Labour are defending both seats. Ukip declined to comment when approached by IBTimes UK.
Beat Suzanne Evans to become Ukip's new leader in November.
Served as deputy leader under Nigel Farage.
Named 85th most influential right-winger in 2015.
MEP for the North West of England since 2009.
Has failed four times to get elected to the House of Commons.
Former history lecturer at Liverpool Hope University.