Police have launched an investigation into an allegation of electoral offences relating to the parliamentary by-election in Ealing Southall, west London.
The investigation follows a complaint that details purporting to show the proportion of postal ballots won by each party had been published on the internet.
Under the Representation of the People Act, which governs elections, it is illegal to publish statements relating to the way people have voted before the close of polls, if the statement is based on information given by voters.
The matter surrounds an alleged entry on a blog on the Daily Telegraph's website and people involved in the by-election who allegedly got a look at ballot papers during the verification process on Wednesday, ahead of their being counted.
The blog entry in question is said to have since been removed from the website.
The complaint to police claimed there had been a "clear breach" of electoral law and asked for the matter to be investigated "as a matter of urgency".
In a statement, the Metropolitan Police said: "We can confirm the Metropolitan Police has received an allegation of possible electoral offences in relation to the Southall by-election.
"The allegation will be thoroughly investigated and appropriate action taken."
