Newspapers require to be trouble-makers and use subterfuge, to be able to expose wrongdoers - The Scotsman's editor-in-chief, John McLellan, writes today.

Describing his appearance last week at the Leveson Inquiry in to press standards - prompting, he reveals, a couple of humorous tweets, such as 'the Village People have let themselves go' - McLellan writes: "There seems to be an assumption from some members of the public that subterfuge is by defintion illegal and therefore unacceptable. Nothing could be further from the truth and exposing wrongdoing or bad practices is virtually impossible without guile and imagination from someone."

McLellan also defends, on freedom of speech grounds, publishing SNP MSP, Joan McAlpine's regular column last week, in which she defended herself against accusations she had described Unionist parties as 'anti-Scottish'.

He finishes by saying The Scotsman will decide which position to take on the forthcoming referendum on Scottish independence "when we know what we're dealing with and we've heard all the arguments".