A Football League report released on Friday morning revealed the Sky Bet Championship club spent £3,538,034 on agents' fees.
Staggeringly, that figure amounts to almost a fifth (19.1 per cent) of all spending on agents' fees in the league.
The sum has risen to such a big figure because the club signed a number of big names in the summer of 2012 - such as Jordan Rhodes, Danny Murphy and Nuno Gomes - following their relegation from the Premier League.
Rovers finished in 17th place last season - just four points above the relegation zone - while this year they are 11th in the standings after two wins in five games.
Blackburn managing director Derek Shaw admitted the big-spending approach of last summer did not work.
He said: "After suffering relegation from the Premier League, there was an influx of new signings, including a number of 'high profile' players on lucrative contracts, in the hope that we would make an immediate return to the top flight.
"Regrettably, those moves didn't work out, both in terms of results on the pitch and from a financial point of view, which is something we have worked hard to put right this summer.
"Since Gary Bowyer's appointment as manager in May, he has adopted a very different transfer policy, bringing in a number of hungry, young players, on manageable Championship contracts, and if recent results are anything to go by, the early signs are very encouraging."
Two of the three teams who won promotion last season - Crystal Palace and Cardiff - spent over a million pounds on agents, as did Leeds and Nottingham Forest.
Overall spending on agents by Championship clubs rose by £521,125. Interestingly, the only club in the league to spend nothing on agents was Blackpool, who currently top the table.
League One spending rose by £298,183 to £2,229,019. Promoted side Bournemouth spent the most (£688,666) on agents while Hartlepool and Crewe did not pay a penny.
There was a big drop of £362,161 spent on agents in League Two. That contributed to an overall fall of £170,000 spent on agents' fees across the Football League.
The 2013-14 season is the first year in which the Football League rules on Financial Fair Play come into effect.
Football League chairman Greg Clarke hopes clubs are spending what they can afford on agents.
"Again, this is a considerable amount of money to be leaving the game," he said.
"However, the real challenge is to ensure that such payments are part of a sustainable financial model with clubs only spending what they can afford.
"In conjunction with clubs, we're making real progress towards this goal and now have all three divisions operating Financial Fair Play regulations."