Reuters previously reported that Coutts was closing Farage's accounts mainly for commercial reasons, citing a source familiar with the matter.
The BBC previously reported Farage had fallen below the financial threshold required to be a customer of the private bank - something Farage said he had had no knowledge of.
A Coutts spokesperson told Reuters that its ability to respond to Farage's fresh claims were restricted by obligations to protect client confidentiality.
Farage told Reuters the issue "raises very broad questions about our banks and how deeply political they have become."
Farage previously said he believed it was because he was deemed a "politically exposed person" (PEP), meaning banks have to apply additional scrutiny to accounts.
Persons:
Nigel Farage, Coutts, Farage, Donald Trump, Iain Withers, Sinead Cruise, David Evans
Organizations:
Brexit Party, NatWest Group, Twitter, Reuters, BBC, Farage, Britain's Daily Telegraph, Thomson
Locations:
Russia