T.B Joshua:'Committing abortion when you are raped is double sin'

On the 8th of this month we published a story in which Pastor Chris Oyakhilome said it wasn't a sin to abort a baby who is the product of rape""

"No child should be brought into this world by force, if a lady has been raped, it is left for her to make a decision of whether to keep the baby or not."

Pastor TB Joshua disagrees on this issue as he answered the question on his official twitter page

 "Committing an abortion when you are raped is a double sin. 

Now which is a double sin?