'Alf' star Benji Gregory found dead at 46

July 11 (UPI) -- Former child actor Benji Gregory, best known as ALF's Brian Tanner, has died, his sister confirmed in a social media post.

Gregory and his service dog, Hans, were found dead in the actor's car, his sister Rebecca Hertzberg- Pfaffinger said. The cause of death remains unclear. Gregory was 46 years old.

The car was discovered June 13 in a bank parking lot in Peoria, Ariz.

"We believe he went there the evening of the 12th to deposit some residuals," Hertzberg-Pfaffinger wrote in her post. "...and never got out of the car to do so. He fell asleep and died from vehicular heatstroke."

That day, the temperature peaked around 109 degrees, People reports.

ALF, which ran on NBC from 1986 to 1990, chronicles the doings of ALF, a Melmac alien named Gordon Shumway, who crash-lands into an American family's garage.

In addition to Gregory, the show starred Paul Fusco, Max Wright, Anne Schedeen and Andrea Elson.

As an actor, Gregory also appeared in shows like Punky Brewster and movies like Jumping' Jack Flash. Variety said he also served in the U.S. Navy.

"It is with a heavy heart my family has suffered a loss way too early," Hertzberg-Pfaffinger wrote. "Ben was a great son, brother and uncle. He was fun to be around and made us laugh quite often. Still, going through his things, I find myself laughing at little videos or notes of his, in between crying."

She told various outlets that her brother had been living with depression and bipolar disorder and often had trouble sleeping.