Speaking about the project, Brutten-Hall said that while The Letter is, "based on fact, it is fictional. We've used poetic license to tell the story."
The actor also added that the film has a very low budget, with it being funded by him and his wife.
"Luckily, that money is only going towards props, costumes and location sets. As far as the equipment, we already have that as we have our own production company. The great thing with modern technology, though, is that there's more you can do with it. You are going to get quality. It's not going to be something you see on Youtube, with a few people mucking around in jumble sale costumes in their back garden… It's not going to be An Adventure in Space and Time part two, but it will be the same quality. It could be a distant cousin."
The Letter is not affiliated with either the BBC or Tom Baker himself. Brutten-Hall has clarified, though, that his script has "gone through a copyright solicitor to make sure we're not infringing on anyone's rights. It is purely a tribute film."
"Anything used in terms of Doctor Who will obviously be used in a documentary style, so the police box is not the Tardis, it is a prop that is used to tell the story."
Tom Baker's agent has told RadioTimes.com that, "We know virtually nothing about it and they certainly do not have our permission." The makers behind The Letter, however, have said that they will make contact with the actor at some point.
The Letter is scheduled to premiere in the West End at the end of the year.