Jersey trust companies are being urged by the UK Inland Revenue to look at how some accounts were set up. The UK tax office is concerned it is losing income because of offshore trust accounts opened by people in the UK.
The office is tightening up loopholes on inheritance tax where people avoid paying it by opening such accounts.
Although trust companies do not allow UK investors to do this any more, the office is investigating accounts set up before regulations were tightened up.
Tax investigators said the UK Inland Revenue was aware of about 8,000 trust accounts set up over the last 20 years.
Lawyers for the tax office have written to trust companies asking them to supply details before they decide whether to take action.