Far-right group Britain First has been fined £44,200 by the Electoral Commission for failing to comply with the law that oversees elections.
Britain First was fined by the watchdog for multiple offences committed while it was a registered political party in the period up to November 2017.
Although it has since de-registered, Britain First remains responsible for its actions during that period, the commission said.
The fines include a maximum £20,000 for failing to comply with a notice requiring Britain First to provide information to the commission.
There was also an £11,000 penalty for failing to keep accurate financial records of transactions in 2016.
Failing to provide quarterly donations reports in 2016 resulted in a £7,700 fine – around £200,000 of undeclared donations were discovered by the commission’s investigation.
And a £5,500 fine was imposed for failing to have its 2016 statement of accounts audited.
Louise Edwards, the Electoral Commission’s director of regulation, said: “Today’s announcement concludes a thorough investigation into Britain First’s financial affairs which has resulted in us finding multiple breaches of the law.
“Registered political parties must provide full, accurate data on their donations and accounts so that voters can see where their money comes from.
“Britain First’s inability to meet certain basic requirements led to a disappointing lack of transparency into the party’s finances.
“The party’s failure to comply with a statutory notice is a serious offence and shows a disregard for the law.
“Throughout our investigation, we saw little to suggest that Britain First appreciated that if it wants to contest elections, it must meet its legal responsibilities, which is why we have imposed the penalties that we have.”