“HEROES” star Greg Grunberg, who plays mind-reading cop Matt Parkman on the sci-fi suspense series, is suggesting the show may be finished.

On a twitter to fans yesterday, Grunberg wrote: “Winding down shooting Season 3 Heroes. Tough to say goodbye to crew not knowing if any or all of us will return next year. Hope all.”

The posting was an immediate sensation, the first clue to the fate of “Heroes” – one of TV’s most passionately followed series but one that has been suffering in the ratings of late.

NBC has yet to say if it will renew the show next year and the Grunberg message seemed to indicate that people in the cast were pessimistic about its future.

A short while later, the actor posted a second message that tried to deal with the fan frenzy.

“Don’t get me wrong, ‘Heroes’ IS coming back next year, but some crew take other jobs, so it’s tough,” he wrote.

The show hit its all-time lowest ratings last Monday, dropping below 7 million viewers for the first time.

Because the show has a big cast and films in a number of locations, it is among the most expensive dramas on TV to produce and its rating spiral makes it difficult to justify the high cost of making “Heroes.”