An audit it requested by the Fair Labor Association

Apple has defended its supplier, but an audit it requested by the Fair Labor Association found that Foxconn workers were subjected to forced overtime, frequent accidents and unrealistic production quotas.

https://www.voanews.com/a/invitation-trump-to-announce-foxconn-plant-in-wisconsin/3959993.html

I don't know why 'an audit' is followed 'it' (two subjects?).

Would you please help me?
Thanks!

PS I also posted the same question on https://www.usingenglish.com/forum/threads/252171-an-audit-it-requested-by-the-Fair-Labor-Association?p=1334681#post1334681, but all of your answers are unique to me. Hope we can discuss with each other. Thank you.