The Pentagon told the New York Times on Wednesday that Berlin rapper Denis Cuspert, also known as Deso Dogg, is believed to have survived an air strike last year in Syria.
The US Defence Department previously reported that the rapper had been killed in an air strike near Raqqa last October.
Cuspert had left Germany and joined the terrorist group in 2012, appearing in various videos including one in which he held a severed head.
He was reported to have helped recruit German fighters and threatened US President Barack Obama as well as American citizens.
Jihadist sources had also claimed Cuspert died in 2014, but later retracted the claim.