The millionaire businessman at the centre of the scandal over secret donations to British Prime Minister Gordon Brown's Labour today laid the blame at the party's door.
Property developer David Abrahams said it was the party's job to check donations and that he was not aware he had risked breaking the law by giving money through third parties.
Scotland Yard has been asked to investigate revelations that Mr Abrahams donated £600,000 to Labour through intermediaries.
But, writing in the Guardiannewspaper, Mr Abrahams said the affair - which has battered Mr Brown's public standing - was a "product of cock-up, not conspiracy".
"I trusted the party to ensure that its donations were being received and spent in the manner in which they were intended, as anyone in my position would," he wrote.
He earlier told Channel 4 News that Mr Brown's chief fundraiser Jon Mendelsohn knew about his method of making donations in April - five months earlier than Labour said it did.
But the Guardiansaid Mr Mendelsohn flatly denied Mr Abrahams' statements over the timing of their discussions. Mendelsohn earlier suggested he only knew about Mr Abrahams' method of donating to prominent members of the Labour party via "agents" in September.
The Labour Party was not immediately available for comment on Mr Abrahams' statements today. The police investigation is likely to involve Mr Mendelsohn and will seek to establish exactly who knew about the donations that might have breached electoral laws.
Electoral Commission rules require those making donations on behalf of others to give details of the source of the money. Mr Brown has said the funds from Mr Abrahams had not been lawfully declared and would be returned.
A survey this week put the Conservative Party 11 percentage points ahead of Labour - its biggest lead since Margaret Thatcher was at her most popular in the 1980s.
A number of senior Labour figures have become embroiled in the row, and opposition parties have stepped up their criticism.
Deputy Leader Harriet Harman has said she acted in good faith in accepting a 5,000-pound donation from Mr Abrahams through a go-between, a move newspapers said had involved Mr Brown's campaign co-ordinator.
And on Thursday, Work and Pensions Secretary Peter Hain said he had failed to register a 5,000-pound donation from Labour's chief fundraiser because of an administrative error.
The scandal is the latest in a series of setbacks for Mr Brown, who has also presided over the Northern Rock disaster - the first run on a bank in Britain in more than a century - and news last week the government has lost computer discs containing the personal details of 25 million people.