Steven Woolfe MEP, the bookies' favourite to be the next leader of UKIP, has missed the deadline to submit his forms to put himself up for the role.
Those wanting to take over from Nigel Farage had to hand in their application alongside the names of 50 supporters by midday on Sunday, but Woolfe experienced some "technical problems" that meant he couldn't upload his documents until 12:17pm.
The MEP, who is also UKIP's migration spokesperson, was already facing questions over whether he is eligible to stand as UKIP leader as he unintentionally allowed his membership of the party to lapse for over a year.
However, a spokesperson for Woolfe insisted that the MEP will still be on the ballot in the forthcoming election despite the latest setback, saying: "Steven Woolfe remains a candidate in the UKIP leadership contest.
"He submitted his application form at 11:35am this morning, in advance of the midday deadline. However, due to technical problems on the party system, it did not successfully go through until 12:17pm.
"Mr Woolfe was speaking to party officials responsible for handling the application process throughout this time and right up to the deadline. He informed them that he was having technical problems.
"These problems were finally resolved and the paperwork submitted."
Channel 4's political correspondent, Michael Crick, reported that Woolfe had been told his nomination was ineligible because of the delay.
I have had it confirmed that Steven Woolfe has been told his nomination for Ukip leader was disqualified as it arrived beyond noon deadline
However, a source on Woolfe's campaign insisted that Crick's suggestion was incorrect, saying: "A vetting panel will meet at midday on Tuesday to rule on the eligibility of all candidates."
Woolfe supporter and fellow UKIP MEP David Coburn expressed his sympathy for Woolfe, telling BuzzFeed News: "I can never get the UKIP website to work and neither can my partner, who is former head of tech at a major corporation."
The other candidates expected to be fighting to replace Farage include obscure councillor Lisa Duffy and MEPs Jonathan Arnott and Bill Etheridge. The final list is expected to be formally announced on Tuesday.
BuzzFeed News has contacted UKIP to confirm whether or not Woolfe has been disqualified because of the application error.