Peter Brady is an agent with British Intelligence.
From IMDB: "British scientist Dr. Peter Brady, while working on an invisibility formula, suffers a tragic accident which turns him invisible. Unfortunately, there is no antidote, so, while working on a method to regain his visibility, he undertakes missions for his government stopping bad guys."
From Wikipedia: "The series follows the adventures of Dr. Peter Brady, a scientist who is attempting to achieve invisibility with light refraction. However, the experiment goes wrong and turns him permanently invisible. He is initially declared a state secret and locked up, but eventually convinces the UK government, represented by Sir Charles Anderson, to allow him to return to his laboratory and search for an antidote ("Secret Experiment"). Almost immediately, British Intelligence recruits him for an assignment ("Crisis in the Desert"), but soon security is breached ("Behind the Mask") and he becomes a celebrity ("Picnic with Death"), consequently also using his invisibility to help people in trouble, as well as solve crimes and defeat spies for his country."