Professor John Sulston said that the run for patent would inhibit important research.
US-based Dr Craig Venter led the artificial life form research, details of which were published last week.
Sulston and Venter clashed over intellectual property when they raced to sequence the genome in 2000.
Venter led a private sector effort, which was to have seen charges for access to the information, while Sulston was part of a government and charity-backed effort to make the genome freely available to all scientists.
"The confrontation 10 years ago was about data release," the BBC quoted Sulston as saying.
"We said that this was the human genome and it should be in the public domain. And I'm extremely glad we managed to pull this out of the bag," he added.
Now the old rivals are at odds again over Venter's efforts to apply for patents on the artificially created organism, nicknamed Synthia.
And Sulston, who is based at the University of Manchester, has said that patenting would be "extremely damaging".
"I've read through some of these patents and the claims are very, very broad indeed," said Sulston.
"I hope very much these patents won't be accepted because they would bring genetic engineering under the control of the J Craig Venter Institute (JCVI). They would have a monopoly on a whole range of techniques," he added.
A spokesman for Venter, of the J Craig Venter Institute (JCVI) in Maryland and California, said: "There are a number of companies working in the synthetic genomic/biology space and also many academic labs.
"Most if not all of these have likely filed some degree of patent protection on a variety of aspects of their work so it would seem unlikely that any one group, academic centre or company would be able to hold a 'monopoly' on anything.
"As the JCVI team and Dr Venter have said, open dialogue and discussion on all issues surrounding synthetic genomics/biology, including intellectual property, is very necessary for this field so these questions and discussions are all very important."
Sulston made the comments at the Royal Society in London where he was discussing a report entitled 'Who owns Science?'. (ANI)