According to Helen Cutter, there was human technology from the future which could be used to clone a human. (Episode 3.3) To create the clone, a sample of the original's DNA (such as saliva traces or hair) was required. (Episode 3.2) A clone would be genetically, and therefore biologically and physically, almost completely identical to the original they were cloned from, but their psyche and personality would never be like the original's. It was unknown how long a clone would take to grow/be copied but one clone appeared to be created extremely fast, as Helen's clone of her husband was fully grown, mature and active within a matter of days (However, it could have been in another time period for an unknown amount of time). (Episode 3.3)
The clones created by Helen Cutter using stolen future technology possessed very limited intelligence, seeming to be unable to function, behave or act normally or appropriately without their master's commands or instructions (for example, Nick's clone could not on his own adaptively behave like the original in social interactions, only stating, in a monotone, basic facts about Nick Cutter). As such, the clones would only talk if asked a question or told to due so. Helen's clones also possessed little to no free will or mind of their own, and would almost automatically obey any commands issued by the voice of their creator. Though this meant the clones would be loyal to and immediately obey their master's commands without question, it could also be used against the clones, as their lack of free will and individual intelligence meant they would obey audio recordings of their master's voice as instantly and competently as their master's commands in person. (Episode 3.3)
Despite clones' lack of intelligence and independence, they did seem to possess at least a small amount of independent empathy and instinctive emotions inherent in all humans. Nick Cutter's clone, upon being told by Nick that life was better than death, chose to give the original Nick time to escape before the clone committed a suicide-bombing on Helen's orders; and one Cleaner Clone, when ordered by Helen to kill himself as a test of loyalty, showed an instinctive hesitance to comply, indicating that clones did to a level inherit humanity's fundamental fear of death. (Episode 3.3)
- Cleaner Clones - Multiple clones of the late mercenary known as "the Cleaner", created by Helen Cutter as her own army. One of the Cleaner Clones was killed by Hilary Becker while infiltrating the Anomaly Research Centre, (Episode 3.2) another committed suicide under Helen's orders as a test of loyalty, and the other Cleaner Clones were all apparently killed by a bomb explosion in the ARC. (Episode 3.3)
- Nick Cutter Clone - A clone of Professor Nick Cutter, created by Helen from DNA samples at Nick's house, to help her infiltrate the ARC by impersonating the original Nick. The Cutter clone killed himself by detonating a bomb inside the ARC to complete his mission. (Episode 3.3)
- When the Cleaner Clones were first seen at the end of Episode 2.7, it was thought by some fans that the multiple Cleaners were the original Cleaner, taken out of various points of his timeline by Helen, before Episode 3.3 confirmed that the Cleaner army were genetic clones.
- There are many fan theories that some people and creatures were cloned but were never confirmed as clones, including: Stephen Hart, based on Helen's neutral response in Episode 3.3 to Cutter's fear that she'd cloned Stephen; the Future Predators in Series 3, based on Helen's claims that they were originally artificially created by a future Anomaly Research Centre; and the second Matt Anderson which Matt saw in Episode 5.6.