Private companies exist to make profits for their shareholders, but the role of government is to act in the wider interest of the public.

The day-to-day grind of this work is not carried out by politicians, but by the network of quangos, agencies and regulators set up to act on our behalf.

Think of any industry - water, energy, the environment - and there will be bodies created for the purpose of tilting the scales away from private interests.

But for this separation of powers to function, there must be a clear distinction between regulators and the companies they monitor.

As we reveal today, these walls are not always as sturdy as they should be. Food Standards Scotland was established in 2015 to advise on safety, standards, nutrition and labelling in relation to what we eat.

To this end, FSS last year called on Ministers to "actively consider how a sugar tax may be introduced and at what rate". This recommendation was made in light of Scotland regularly missing its healthy eating targets.

However, while this move was laudable, it is concerning that one of the board members has financial links to the confectionary and soft drinks industries, whose products are full of sugar.

Dr Carrie Ruxton is a nutrition specialist who has advised chocolate manufacturer Ferrero as part of her outside work.

Let us be clear: Dr Ruxton has done nothing wrong. She has properly declared her outside interests, which are available on the FSS website. She also chaired a panel event for the British Soft Drinks Association.

The issue at hand is whether Dr Ruxton, given her links, should have been made an FSS board member in the first place.

The Scottish Environment Protection Agency (SEPA) also recently ran into trouble over the perception of a conflict of interest.

As we revealed, SEPA brought in the Scotch Whisky Association (SWA), which represents corporate drinks firms, to interview candidates to head a unit overseeing pollution permits for companies.

This was in spite of SEPA, in 2014, rating the pollution performance of seven whisky distilleries as poor.

Appointments to regulators should always be made on merit, but a greater consideration must be given to avoiding obvious conflicts of interest.