A Bronx cop is accused of being so lazy that he tossed a key piece of evidence in a domestic-violence case — a machete — into a park pond so he wouldn’t have to waste time registering it at the precinct, it was revealed on Friday.

Officer Elbert Tim, 33, is being investigated by the NYPD’s Internal Affairs Bureau and the Bronx DA’s Office — after police divers were forced to search a pond at Crotona Park for the missing weapon earlier this week, sources told The Post.

His partner, who was not identified, also is being eyed in the probe.

“[Tim] took arrest evidence in a domestic incident out of the home and didn’t even voucher it, just tossed it in a lake,” a law enforcement source said.

“I’ve never heard of a cop doing this. … That’s official misconduct.’’

Tim and his partner responded to a domestic dispute in Charlotte Gardens on Valentine’s Day, when Jaron Johnson allegedly pointed the machete at his stepsister, Quendre Hodges, and screamed, “If you don’t move out, I will kill you!” according to a criminal complaint.

Neither cop seemed particularly interested in taking down her complaint, Hodges said.

“They never asked me my name,” the 42-year-old told The Post. “They never asked nothing. One officer wanted to put me out. The other one didn’t.”

At Hodges’ behest, the officers left the apartment with her stepbrother’s machete and a baseball bat, which they put in their patrol car, she said.

Tim’s downfall came when Hodges decided to file charges against her stepbrother the next day — and that’s when investigators at the 42nd Precinct asked where the machete was, sources said.

Tim admitted to investigators — and The Post — that he threw the bat and machete in the pond.

But the officer said he can defend his actions.

He insisted that Hodges “never alleged any type of crime whatsoever” when he and his partner showed up to the apartment.

He said Hodges was being evicted — and needed help getting her belongings out of a locked closet that also had a machete and baseball bat inside.

“[Johnson] told me he was going to throw the machete in the trash,” Tim said. “I just took it somewhere secluded so nobody could get it. I never really thought anything of it.”

He admitted to tossing the machete in the lake, adding that he believes the machete was ultimately recovered.

Tim said he expects to be punished.

“I didn’t get modified [duty] yet,” he said. “I think I will eventually.”

Meanwhile, Johnson was charged earlier this month with menacing and harassment. He said Hodges wasn’t supposed to be staying at the apartment, which belongs to his mom.

Even he said the officers’ who responded to his mom’s place weren’t eager to take down a report.

“They didn’t do no paperwork,” he said.