The lead detective in the O.J. Simpson murder case is throwing cold water on a new bombshell claim that O.J. had help covering his tracks … and he’s not mincing words.

Retired LAPD detective Tom Lange joined us on “TMZ Live” Monday, and we asked how much stock he puts in the theory that Joseph “Joey” Ippolito helped O.J. dispose of evidence after the 1994 murders of Nicole Brown Simpson and Ron Goldman.

His answer? “Pretty close to zero.”

Tom admits the allegations make for an interesting story, but he says there’s one glaring problem — there’s no actual evidence.

As TMZ previously reported, a New York Timesinvestigation revealed claims from Joey’s brother, Sam Ippolito, who says Joey came home the night of the murders with bloody hands and a heavy bag, which Sam later dumped.

Tom tells us Joey’s name actually came up in several tips during the original investigation … but nothing linked him to the killings, and LAPD never interviewed him.

And when Harveysuggested someone must have helped O.J. ditch the evidence, Tom fired back with a detail from the original investigation.

Tom says a witness spotted O.J. at the airport shortly after the murders, allegedly pulling items from a bag and tossing them into a trash can before boarding a flight to Chicago.

Nobody knows what he threw away … but Tom says that’s a whole lot more compelling than an unproven story about a mystery cleanup man with ties to O.J. and the mafia.