Yes. Unfortunately Justeft is correct. UK taxpayers can owe tax on the dividends obtained by accumulating ETFs and reinvested, ie dividends that you never see. Read the section here titled What about ETFs?
The taxable amount is known as excess reportable income and the amount you need to report for tax can be found on the web pages of the ETF provider.
It would not make sense that accumulating ETFs should somehow escape the same tax liability as their distributing siblings.