"den of corruption" is correct and usable in written English.
You can use the phrase in any context where you would like to refer to a place, or an environment, in which something morally wrong or corrupt takes place. For example, "This city government has become a den of corruption, with widespread kickbacks and payoffs."
Because Westminster is not a rancid den of corruption, nor a conspiracy against decent people.
We can now say with certainty that it is a den of corruption".
The Bureau of Indian Affairs (BIA), which oversaw such slums, was a den of corruption and incompetence.
Voters see Congress as an ineffectual den of corruption, as they do the judiciary despite a number of courageous judges who risk their lives trying to dispense genuine justice.
The Prohibition Bureau, when Ness joined it, was widely regarded as a den of corruption and incompetence.
Ayatollah Ruhollah Khomeini, the father of Iran's revolution, once tried to ban all beauty parlors, calling them "dens of corruption".
Throughout their existence, critics said the boards too often became dens of corruption and back-room deals, and when the mayor took control, they were replaced by parent councils that were virtually powerless.
Yesterday, those vague suspicions were given more credence as police officials described the cafe as a den of petty police corruption, with officers running license plate checks and fixing traffic tickets in exchange for free meals, power tools that they believed had been stolen, and other items of value.
Christie's, as Sewell describes it, was a den of amateurism and low-level corruption, its profits feeble enough to dictate that one's Christmas bonus consisted of a turkey.
But the sunny disposition began to sour last October, when Mr. Bowen, 50, filed a lawsuit against the Parking Authority, charging that the agency was a den of patronage, bid rigging and corruption.
