The US authorities refused to comment on media reports that Pakistani-American convict in the 2008 Mumbai terror attack case David Coleman Headley was battling for his life after being attacked by inmates at a detention centre on Monday.
"We are not able to locate information about this individual," the Metropolitan Correctional Center in Chicago said in a brief email response to PTI when asked about the incident.
According to some media reports, David Headley was attacked on July 8 by two other inmates.
The reports said he suffered serious injuries and was rushed to North Evanston hospital, where he was admitted to the critical care unit.
David Headley has been sentenced to 35 years in prison by a US court for the 2008 terrorist attack on Mumbai that killed more than 160 people.
David Headley - who recorded various Indian cities, including Mumbai before the 26/11 attacks - was arrested in 2009.