BBC Wales parliamentary correspondent
A former senior aide to Peter Hain has denied that his Labour deputy leadership campaign was "chaotic".
Peter Hain is to send full details to the Electoral Commission later
And Phil Taylor blamed his successor as campaign manager for a failure to declare donations properly.
Mr Taylor, who was replaced by Steve Morgan, says all donations were declared properly to the Electoral Commission while he was in charge.
Mr Morgan had earlier said he was brought into the Neath MP's campaign "to bring order to the chaos".
Mr Hain, who is Welsh Secretary and Work and Pensions Secretary, said he blamed "administrative failings", which he described as "deeply regrettable".
Although he declared donations of £82,000 for the campaign, the Guardian newspaper claimed the real figure may be more than £100,000.
Responding to claims of chaos, Mr Taylor told BBC Wales: "Not on my watch.
"By the time I left we'd received legally and had declared £37,000 of donation and we hadn't received a single penny in donations that was not declared at the time I left, so there was no chaos of any kind."
Mr Taylor said: "I just, in all conscience and honesty, couldn't stay on board with the campaign and work with Steve Morgan.
"It gives me no pleasure to say but the things that are becoming public now in a way vindicate that feeling I had at the time.
"This was a minefield and a territory I wanted to keep close to my chest and manage myself.
"As soon as it became clear I wouldn't have total control over that area of the campaign, that combined with my concerns over the direction of the campaign, meant that I felt no option but to leave."
Peter Hain (right) eventually lost the contest to Harriet Harman
Mr Taylor, who worked in government with Mr Hain at the Wales and Northern Ireland Offices, decided to break his silence after hearing Mr Morgan's interview with BBC Radio Wales.
Mr Taylor, a former special adviser, added: "You know it's widely believed there were a number of donations made during that period in June that weren't declared. Now I can't prove that. I don't know that.
"We need to wait and see what the campaign actually says when they finally publish their list of results.
"But I think it's inconceivable to suggest that the person who ran the campaign throughout that period didn't know that donations were coming in and failed to declare them."
Mr Taylor said he knew Mr Hain "incredibly well" and "the Peter I know would have had nothing to do with any of this."
"He is one of the most straightest, honest, decent men that I have ever met and I just cannot understand what went on in that campaign," he said.
He insists Peter Hain should not be blamed for the failure to declare donations but acknowledges that as the candidate he is legally responsible.
"What I'm clear about is that there won't be any guilt attached to Peter personally," he said.
"You and I both know that politics doesn't work like that and we'll just have to wait and see what the fall-out is when it becomes public about the donations that weren't declared."
On Tuesday, Steve Morgan said there was a "truism" that he was brought in half way through Mr Hain's campaign "to bring order to the chaos".
Mr Morgan told BBC Radio Wales: "The issue here is not that anybody is trying not to disclose things but how will all of us manage with donations that come into a campaign after the campaign has officially closed down.
"Peter has been very open about this whole process, more so than most and I think he's been fully cooperative with the Electoral Commission over some of these key issues, which none of us have experienced before, donations in kind being one of them."
Mr Hain apologised for failing to register some of the donations given to his Labour deputy leadership campaign.
He said he blamed "administrative failings", which he described as "deeply regrettable".
Although he declared donations of £82,000, the Guardian newspaper claims the real figure may be over £100,000.
Mr Hain said he had undertaken a full audit and would be providing the details to the Electoral Commission of late declarations by the middle of January.
"I reiterate that this is deeply regrettable and I sincerely apologise," he said.