O.J. Simpson Estate Hit With $500k Tax Lien, Says Executor

O.J. Simpson avoided paying Nicole Brown Simpson and Ron Goldman's families millions when he was alive -- and now, from beyond the grave, he might be dodging them again ... TMZ has learned.

While Malcolm LaVergne -- O.J.'s longtime lawyer and now executor of his estate -- made it clear he intended to talk money with Nicole and Ron's respective loved ones ... Malcom says an unforeseen tax debt is creating a new hurdle.

Malcolm tells TMZ ... the state of California has a massive tax lien against Simpson's estate for $572,402.69 -- which he says could derail his plan to settle part of the $33.5 million judgment O.J. owed his victims' families after the 1997 wrongful death lawsuit.

Remember, though O.J. was acquitted in his murder trial, he was later found liable for Nicole and Ron's deaths in a Santa Monica civil court.

Although the judgment was $33.5 million, interest on the unpaid debt has ballooned to a reported $100 million.

Malcolm says his lawyer met with the Goldman family -- as well as an assignee for Ron's mom Sharon Rufo, who auctioned off her rights to the judgment -- earlier this month at his Las Vegas office. He says a rep for Nicole's estate did not show up, despite being invited.

We're told they reviewed Simpson's tax returns, 401K, bank statements and more -- and the Goldman lawyer and Sharon's rep were told they'd be accepted into the estate ... with the intention being to satisfy their judgments.

The timeline for doing so remains unclear, though. Malcolm says he's still investigating how much the estate is worth, especially amid the tax lien.

He says he was "broadsided" by the $500K debt, and might need to go to court to deal with it before "it wipes out any idea I had in my head to pay Goldman something" -- which he says "would be nice."

Right now, the strategy is to fight the lien ... which means a court will have to decide before any sum can be handed over to Ron's family members.

Malcolm is optimistic, however ... believing there are some hidden gems in the estate that could help cover some of the costs. He says O.J.'s Heisman trophy (though it might be a replica), paintings, golf clubs, black SUV, grand piano and more could potentially be liquidated and bring in a very pretty penny.

Fans of O.J. might be interested in getting their hands on some of his more personal items -- including video reels, furnishings and old photos of O.J. with Nicole, Kareem Abdul-Jabbar, Muhammad Ali, etc.