Three's company: Louis meets Neil and Christine
The couple gave Theroux unprecedented access to their lives as they were embroiled in a scandal over indecent assault allegations, which were later dropped.
The former MP told BBC One's Breakfast programme that he allowed the cameras access to their lives so they could give their side of the story.
"We took the view that, if it was all going to be played out on the front pages of the newspapers anyway, we would get our retaliation in first," the disgraced former Tory MP said.
The couple's arrest, on 10 August, took place in the full glare of publicity, and the allegations were reported in lurid detail.
The Hamiltons were accused by Nadine Milroy-Sloan of indecently assaulting her at a flat in Ilford, Essex, earlier in the year.
Neil Hamilton said the public nature of the arrest had prompted the couple to respond in an equally public fashion.
"We had to decide there and then how we were going to play this," he said.
"If there hadn't already been a posse of photographers and reporters outside the police station, we may not have had Louis recording the event."
'Flirty'
Christine Hamilton said it had "added "enormously to the strain" to come home to find "dear Louis" filming them.
She dismissed the "fuss" in several newspapers over scenes from the documentary in which she is seen hugging presenter Theroux as her husband looks on.
Describing herself as "a very flirty person", she said one of the joys of being happily married was that "you can flirt away, and nobody takes you seriously".
"After a few drinks and dinner, that would be what I might do to anybody on the sofa.
"People make such a fuss about a little bit of bodily contact," she concluded.