Guardian. (Which you say you read Steve)

"Labour leadership: infiltration shambles puts vote at risk, says Lord McConnell, Former Scottish first minister "

"With the contenders set for an emergency meeting to discuss efforts to weed out infiltrators,"

"More than 120,000 people have paid £3 to take part in the vote, along with more than 189,000 members of unions and other affiliates, swelling the electorate to more than 600,000.

According to Newsnight reports, more than 3,000 voters have been rejected, though Labour said on Friday the figure was half that number.
The first wave of rejections, known as #Labourpurge on social media, included removing members who had been Conservative, Green and Socialist Worker party candidates, and those expressing support or raising money for rival parties."

"Leaked meeting notes from the party's procedure committee show it has been inundated and the system is overstretched, with the New Statesman reporting that almost every member of Labour HQ's slimmed-down post-election staff has been drafted in to help wade through the roll of new supporters.
Murad Gassanly, a councillor in Pimlico, south London, told Newsnight he estimated 20% of supporters who had joined the local branch were "dubious", with evidence of them supporting other parties found on Google and social media."

"We are also concerned that, given the party's limited resources and the effort required to investigate applicants, this could result in the integrity of the contest being called into question, and the outcome subject to legal challenge."
http://www.theguardian.com/politics/2015/aug/22/labour-leadership-infiltration-shambles-lord-mcconnell