Rats high on marijuana at infested US police building

Rats have managed to get into confiscated marijuana at New Orleans' aging police headquarters, munching the evidence as the building is taken over by mould and cockroaches, the city's police chief says.

"The rats eating our marijuana, they're all high," Police Superintendent Anne Kirkpatrick told New Orleans City Council members.

Kirkpatrick described vermin infestations and decay at the offices that have housed New Orleans police since 1968, saying officers have even found rat droppings on their desks.

The police department did not immediately respond to an emailed request Wednesday for more information on how they discovered marijuana was eaten by rats or whether any cases were impacted.

City officials are taking steps to move the department to a new space. That's been a priority of the police chief since she took office in October.

The chief said her 910 officers come to work to find air-conditioning and elevators broken. She told council members the conditions are demoralising to staff and a turnoff to potential recruits coming for interviews.

"The uncleanliness is off the charts," Kirkpatrick said, adding that it's no fault of the department's janitorial staff.

"They deserve an award for trying to clean what is uncleanable."

The city council is weighing a proposal to spend $US7.6 million ($A11.5 million) on a 10-year lease to temporarily relocate the police headquarters to a pair of floors in a high-rise building downtown.

The council's Criminal Justice Committee agreed on Monday to advance the leasing proposal to the full City Council for a vote, The Times-Picayune/The New Orleans Advocate reported.

Kirkpatrick says the rental agreement would give the department time to come up with plans for a new permanent headquarters.

Ron Harrison, global technical director for Orkin Pest Control, told The Associated Press he hasn't encountered someone reporting rats eating their marijuana though the company has pest control contracts for some greenhouses that grow it.

Harrison said the New Orleans situation isn't completely shocking since rats are omnivores, and that the rats may experience the same effects from the marijuana as humans, depending on what form it was in.

"From understanding the biology of the rat and how it's somewhat similar to us, I would think based on the amount or concentration they take in, it would be somewhat similar to what humans experience," Harrison said.