'Big Brother' Star -- I Wish Evel Dick Stayed In Game ... After HIV Diagnosis

One of "Evel Dick" Donato's former "Big Brother" housemates tells TMZ ... she wishes Dick would have STAYED in the BB house after learning he was HIV positive -- but Dick says he didn't have a choice.

Donato -- who won BB in 2007 and then rejoined the cast in 2011 -- left the show very early into Season 13 when he was informed by producers that blood tests showed he had HIV.

We spoke with Rachel Reilly -- who was competing in the house at the time -- who tells us she wishes Donato would have stayed in the game.

"If he had a meeting with everyone it would have been a way to give the disease a voice," Reilly said ... "It's reality TV."

She adds, "I think it's cool he is talking about it 3 years later and I hope this changes people's lives. I think it's brave of him."

We also spoke with Evel Dick on "TMZ Live" moments ago ... who told us he didn't get a choice to stay in the game -- producers told him he had to leave.

But he also says he wasn't ready to go public with the information anyway ... "This was the most shocking news I've ever been told. I needed time to digest."

Donato says it's already destroyed him in one way -- financially.

For their part, a rep for CBS tells TMZ Dick was not forced to leave the show, but rather made the decision on his own.