‘Catching the Tax Dodgers’ airs on Channel 4 at 10pm on Monday, 14 August. According to the programme information, it will feature Duncan McCallum, described as ‘a veteran customs officer who has cracked drug rings, smugglers and massive duty fraud’.

The description goes on to state: ‘This documentary reveals for the first time the methods HMRC uses to find out who is and isn't paying tax and how they target those individuals.’

The documentary has been some time in the making. It was initially commissioned from Tiger Aspect Productions in 2014, with a commission to make three one-hour long programmes to be broadcast in 2015.

At the time, Channel 4 publicity said ‘the team behind this observational documentary series has spent twelve months securing unique and unprecedented access to HMRC’.

Channel 4 Head of Documentaries Nick Mirsky said when the announcement was made: ‘Money from taxation funds everything we value most about society, yet the team who collect it have often been viewed with mistrust and suspicion.

‘What is exciting about this commission is that it offers unique access to a group of public servants on whom we are more dependent than ever to help make the nation's books balance. It is a series that is important, fresh and timely - and will take us right into the heart of the battle to make everyone pay their fair share.’

The programme was slated to follow inspectors and investigators on the frontline, with suggestions it would look at the teams targeting the so-called ‘high risk’ sectors, from plumbers and scrap merchants to dentists and doctors, offshore bank accounts and high net worth individuals.

Channel 4 has provided few details of how much of the planned content has made its way into the final documentary, and from the scheduling it appears there is now only one programme, rather than a series.