OCI and name change

[01Lavahd]

Hi,

I have browsed the forums but could not find a case similar to mine, so here goes...

My mum took up my dad's name as her middle name when they got married and she kept that name for her passport.

When she got a British passport and certificate (in 2004), she dropped her middle name and just kept her first and last name.

Recently she was denied OCI on the basis of her name and was told to get a deed poll.

Now the question is whether she needs a deed poll now or as I suspect, an affidavit that says she is the same person with different names?

Any help would be much appreciated.

Thanks.

PS: according to her, she didn't need a deed poll at time of attaining British passport.