Despite speculation, JLS say they have got "no problem" with N-Dubz.
"There is no rivalry, we've got absolutely no problem with N-Dubz at all," said Marvin.
He added: "We haven't said anything that people say we do say."
The rumoured celebrity beef dates back to September last year when Dappy from the grime trio apparently had a go at the boys for miming. More recently it was thought they clashed over Marvin's girlfriend, Saturdays star Rochelle Wiseman.
Aston added the band were too busy writing their album to get involved.