Stormont justice minister David Ford was speaking after Deputy First Minister Martin McGuinness criticised some elements within the Police Service of Northern Ireland (PSNI) for detaining Sinn Fein president Gerry Adams three weeks before the European Parliament elections.
Tensions in Northern Ireland are running high after Adams's arrest, with McGuinness warning that Sinn Fein may be forced to review its support of the PSNI if the situation is not "resolved in a satisfactory manner".
On Friday night a judge granted the police a 48-hour extension of their time to question Adams in connection with the 1972 murder of mother-of-10 Jean McConville, one of Ulster's "Disappeared".
Ford told the BBC's Today programme: "It is normal practice if somebody is likely to be arrested in the course of an inquiry that they are arrested at the start of discussions."
He added: "I don't know whether Gerry Adams thought he was going to turn up at Antrim's serious crime suite, have a wee chat for half an hour and then go off again, but clearly on the scale of the concerns expressed, of the information - which I entirely accept is not yet evidence - it was entirely appropriate that should be followed up in the normal way."
Ford said: "If there are dark forces within policing, I can see no sign of dark forces. I see a police force with very high levels of confidence, higher than the Garda Siochana [Republic of Ireland police] or many forces in Great Britain. And I see a police force carrying out its duties properly and appropriately, following up evidential opportunities where they present themselves."