But driver Romain Grosjean was also not paid by struggling Lotus in 2013, although the Frenchman said last month he kept the problem quiet.
"I never opened my mouth in front of the media because it was my own business, my personal thing," he said.
Indeed, team owner Lopez has now hit back at Renault for suggesting some teams have failed to pay for their new turbo V6 engines this season.
"I said to them if they are going to say things, then name the team that is an issue," he is quoted by the Daily Mail.
"Don't just say 'teams' and then expect people to make their own judgements.
"If there is (a team that has not paid), it must be somebody else, but I'm not even sure there is, to be honest with you," Lopez added.