Creating life calls for patience, and cleverness.
The issue here is one of punishment. If they are caught, they are punished. However, they can only be caught if it can be proven they did something which caused life. The solution is to start modifying the environment around you to encourage life to start on its own. Then there is no longer a causal chain linking the creation of life to them.
Of course, the interesting part is that, with a near immortal lifetime, they would hopefully develop a very refined understanding of what "life" is. Currently, one of our biggest challenges in searching for extraterrestrial life is that we are bound by our lack of imagination -- we only have one example of what "life" looks like. It's built around a bunch of sugars that speak a language using A G C and T. This is quite a boring limited definition for an immortal species.
Consider how hard it is to prove that our ideas aren't, themselves, alive. It sounds silly, until you try to disprove it. Then, suddenly, you start pondering because all of the arguments for why ideas aren't alive can be reframed to argue that we are not, in fact, alive. They even reproduce. There's even an approach called memetics which tries to explain how social and cultural structures form using evolutionary theories. They even explain why that blasted song gets stuck in your head!
So perhaps the scientists need to play around with this. Perhaps they need to instill living ideas in people's heads which encourage them to bring more life to the universe. Spread this far enough, and you'll topple the high council, or whatever body is threatening to imprison you. Or perhaps one of those who fell in love with your idea will dare to risk imprisonment and start playing with those A's G's C's and T's. Honestly, if they do it right, nobody will mind. The best way to spread a living idea is to be kind to other people. Who would ever complain about someone being kind to them? The high council might even support it!
Best yet, the results will be real life, not fake-wishy-washy-life. It wont be life that bends itself to your will simply because you programmed it that way. It will be the vast growing, changing, terrifying force that is life itself, influenced by the scientists' desires but never truly controlled.
Be careful what you wish for!