The Sky Bet Championship club confirmed over the weekend that the 32-year-old was one of six people detained by the National Crime Agency (NCA), who acted on information passed to it by The Sun on Sunday newspaper.
Campbell was bailed on Monday until April but will not play a part in Saturday's clash with Millwall and it is not known if he will feature in Rovers' games in the foreseeable future after they granted him "time off to spend with his family".
In a statement seen by Press Association Sport on Thursday, Blackburn said: "Blackburn Rovers manager Gary Bowyer is today unable to comment on or answer any questions relating to striker DJ Campbell for legal reasons.
"As police investigations are ongoing, you will be aware that reporting restrictions are in place.
"If members of the media persist with trying to ask questions surrounding this sensitive issue, then today's press conference will have to be suspended.
"In light of this week's events, Rovers can confirm that DJ Campbell has been given time to spend with his family and therefore will not be involved in Saturday's Championship fixture with Millwall at Ewood Park.
"The club will be making no further comment."
As part of the investigation, The Sun on Sunday claimed NCA detectives were likely to review a caution Campbell received in the first half of Blackburn's league game against Ipswich on Tuesday, December 3.
Speaking at his press conference on Thursday, manager Bowyer insisted his focus was purely on Saturday's game with the Lions.
"We've focused on what we can control and that's the training," he said.
"It's been in the press but we can't talk about it at the moment. We've just controlled the training and our focus is on Millwall.
"It has shocked everybody. Everybody in the game has talked about it, it's something that shouldn't be in the game but the proper people are going to deal with it."
Rovers' stance on one of their own players under investigation comes in contrast with Oldham's position on winger Cristian Montano, who was suspended without pay by his club on Sunday.
However, Tranmere's Akpo Sodje will be considered for selection against Carlisle on Saturday with boss Ronnie Moore adopting an "innocent until proven guilty" mantra on him and 41-year-old team-mate Ian Goodison, both also arrested as part of the NCA investigation.
"Goodison is injured but Sodje is available for selection," Moore told Sky Sports News.
"The good thing about this country is that you are innocent until proven guilty so we are taking it at this moment in time that there is no truth in what has been said.
"If it comes out that there are one or two things that they have done, then the whole situation changes. But at this moment in time, we will put our arms around them and we get going.
"Everybody was in shock, especially because they are involved at this club, but those players have been fantastic for us.
"But no-one has proven anything and the police haven't charged them, so we just get on with it.
"They are being paid to play football. We have got to back them until someone tells us something else."
Source: PA
Source: PA