Foreign income

Hello. I was filling in my self assessment form and selected no foreign income. When I pushed submit, a message came up saying that HMRC receive information from various bodies and that I may wish to reconsider my answer. I cannot think of any foreign income I have except an Irish domiciled fund held in an ISA. Is it possible that the ISA manager has shared information with HMRC? If not how do I find out what the income is? Thanks.

Hi,
 

Only a UK ISA is tax free and doesnt need declared. income in a foreign account still needs to be declared in the UK  . Thank you.