After convincing the FBI to seize and secure his investigative records, Legislative Inspector General Faisal Khan closed his office Monday with parting shots at Mayor Rahm Emanuel and a City Council that, as Paddy Bauler once famously said, “ain’t ready for reform.”

“The system was rigged from Day One. This office was designed to fail intentionally and the only people who did not get the memo were me and my staff. I do not believe the Council really wants any type of oversight at all,” Khan said, citing investigative rules that tied his hands.

“If they were not happy with me, they should have had my replacement ready to go. Instead of packing up the files, I should be transferring them to my successor. The real goal was to end oversight. The mayor made a number of promises that oversight would not go away. Yet here we are starting [Tuesday] with no oversight. It’s an incredible disappointment that it came to this.”

Khan said it was at his request that FBI agents armed with a subpoena arrived at his office late Friday to haul away computers and hard copies of his investigative files.

Well aware that his days were numbered, Khan said he’s been in “constant discussions with law enforcement  agencies” in recent months about the imminent closing and “what actions would need to be taken” when his tumultuous, four-year term ran out.

“We had a number of investigations that involved criminal allegations. To protect the integrity and confidentiality of those cases, they were given to the FBI by way of subpoena. That was a decision both by this office and by the FBI,” he said.

“I hope all of these investigations come to fruition shortly and the public will be able to see what this office did while it was still in existence. There are a number of good aldermen in Chicago who truly believe in a corruption-free government. But there are another number who betray the public trust and should be held accountable, and I hope they will be held accountable. If they’ve done nothing wrong, they have nothing to be afraid of. But those who have done something wrong should be concerned. They should know who they are.”

Chicago aldermen have seen 30 of their former colleagues march off  to federal prison since 1970. But they were not exactly quaking in their boots to learn that the files of their handpicked and hogtied inspector general are now in the hands of the feds.

“I kind of view it was one last piece of dramatic showmanship by him,” said Ald. Joe Moore (49th), one of Khan’s early targets.

“If there was anything criminal, the FBI would have taken it a long time ago.”

Ald. Proco Joe Moreno (1st), another Khan targets, said the LIG has accused aldermen of everything from bribery and gross neglect to ghost payrolling and abuse of power, only to have the Board of Ethics “throw it out on the face of it.”

“He did a terrible job . . . He overreached in many, many different ways. He did not run a professional department. He did not have professional investigators by any means. He spoke to witnesses off-line, not in in his office. He reached out to them to have coffee and discuss things with them. [Inspector General] Joe Ferguson said that was absolutely unethical and would not be allowed in his office from the most junior investigator,” Moreno said.

Ald. Nick Sposato (38th) said he’s not concerned, either. That’s even though he was one of 29 aldermen who Khan recently accused of accepting campaign contributions that exceeded the $1,500-a-year limit from city contractors.

“That was my landlord who is one of my very good friends who has contributed to my campaign. I know he has a contract with the city. But, I didn’t know he was considered a city vendor. So, I accepted $3,000 from him in 2013. I immediately gave him $1,500 back,” Sposato said.

“I can’t imagine it would be anything to be in trouble for. I rectified the problem and that was it. It was an oversight and I corrected it.”

As for Khan, Sposato said he did as good a job as he possibly could with his hands tied behind his back.

“He was a toothless tiger or a paper tiger, whatever you want to call it,” Sposato said.

Ald. Roderick Sawyer (6th), chairman of the City Council’s Black Caucus, said he won’t lose a wink of sleep knowing that Khan’s files are in the hands of the feds.

“He would have brought it up a long time ago, had he found something truly criminal,” Sawyer said.

“Quite honestly, I thought he did a lot of fishing expeditions that may or may not have led to nowhere. But, it certainly boosted his salary quite a bit.”

A former Queens County prosecutor turned New York City inspector general, Khan was hired four years ago by aldermen hell-bent on keeping Ferguson out of their hair.

He’s been at war with the aldermen ever since.

They accused him of overspending, packing his staff with political operatives and “going fishing” with a blanket request for their employee time sheets dating back years. Aldermen further accused their handpicked sleuth of launching and leaking “penny ante” investigations that embarrassed them unfairly and violated their rights.

Through it all, Khan stood his ground and even filed a now-dismissed lawsuit seeking the $1.7 million he claimed he needed to finish the job. When aldermen stripped him of the power to investigate their campaign finances just months before the Feb. 24 election, Khan declared the move an effort to force him out.

Now that the office is closed, the heat is on aldermen to decide what to do next. Some want to empower Ferguson to investigate aldermen and their employees. Others want to find a replacement for Khan and have already launched a search with a Nov. 30 deadline. Still others have argued that it makes no sense to hire a new Legislative Inspector General until the handcuffs slapped on the old one are removed.

Khan was adamant about what needs to happen next, and it won’t please the City Council’s two most powerful aldermen: Finance Committee Chairman Edward Burke (14th) and Budget Committee Chairman Carrie Austin (34th).

“The proper and immediate solution is to transfer this oversight power to Joe Ferguson. They should immediately call for a vote on this and let the record reflect who is against and who is for this. That will truly let taxpayers know who is for ethical oversight and who is not,” Khan said.

“Thirty-five aldermen wanted this pre-election. Hold their feet to the fire. Now, it’s time to vote.”