If you are the direct beneficiary it should have been declared at the start of the iva.
IVA started March 2011, Completed March 2016 and certificate issued 11 days after final payment. It was not always easy but then some of the best decisions aren't.
You certainly need to speak to your IP company to get this sorted out and you may well lose it.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
This will have to have been dealt with at the time of the IVA and either included or excluded. If you did not declare this it would be a material ommission and could lead to the failure of your IVA and possible bankruptcy. You need to speak with your IP.