Sponsor issues reportedly led to Narain Karthikeyan losing his seat at HRT.
The Indian driver's main backers, Tata and Base batteries, are still showing at the Spanish team's website. Hispania has been contacted for comment.
At Silverstone, HRT regular Vitantonio Liuzzi will for the first time share the garage with Australian rookie Daniel Ricciardo, as part of a new driver deal with Red Bull Racing.
Karthikeyan is officially still on the books as an official driver, amid rumours he might return for the inaugural Indian grand prix in October.
His sponsors Speed, Tata and Base are still showing on his official website, although the Italian magazine Italiaracing claims "economic difficulties" meant Karthikeyan lost his seat.
"When he learned of the economic difficulties of Narain Karthikeyan, Helmut Marko did not think for a second and reached the agreement with Hispania for the debut of his young protege (Ricciardo)," read the report.
Karthikeyan was not available a few days ago, and his management has once again been contacted for comment.