Need e-mail about immigration crime.

Hello guys.
Hope you doing good.

i am asking this question on behalf of my friend.my friend is british since 2005. He got married in Pakistan 2011 and his wife got visa for about two years. when his wife came to UK and after that they separated(Not devorced) after few months and my friend went to pakistan and he thought his wife already left the country which she actually did not. And my friend divorce his wife in pakistan and send divorce papers is her house in pakistan. and now he come to know that his ex wife got extensions while using fake documents in uk, claiming his wife. Now he wants to let Home Office know about her visa extension while using fake documents. so that no further extensions OR ILR can issue.

kindly can you tell me any e-mail OR address to write proper letter to HO,

Thanks in advance.

Kind Regards
ALI

https://www.gov.uk/report-immigration-crime

https://www.gov.uk/visas-when-you-separate-or-divorce

Without his consent/permission her wife visa will definitely be cancelled as it would be counted as crime. She might even be charged with penalty too.