Peta Credlin said to have denied FOI request re Australian Prime Minister Tony Abbott's citizenship status

Tony Magrathea‏ who tweets as @dickybeacholdie had this to say on Twitter on 17 July 2014:

My foi request for Abbotts form RN, renounce British citizenship has been denied by Peta Credlin. Home Office [U.K.] still looking.

The form Mr. Magrathea is referring to is here.