LONDON, April 7 (Reuters) - Britain's Financial ConductAuthority has asked 20 banks and other financial firms to checkif they have any ties to Panama law firm Mossack Fonseca, theFCA said on Thursday.
A massive leak of documents from the law firm detailed howthe world's rich skipped through loopholes to park cash inlow-tax jurisdictions.
"We have written to the firms earlier this week," an FCAspokeswoman said.
HSBC, Britain's biggest bank, has dismissedsuggestions it has actively used offshore structures to helpclients cheat on their taxes.
The bank has said the documents from Panama pre-dated athorough reform of its business model.
(Reporting by Huw Jones; editing by Jason Neely)