Stephanie Pratt has hit out at her brother Spencer.

Stephanie Pratt

Stephanie Pratt

The former MTV 'Hills' star took to Twitter and Instagram to call out "poisonous" family members and although she did not initially mention her brother, she later blasted him when replying to comments.

Stephanie, 31, shared an Instagram quote, which read: "Some of the most poisonous people come disguised as family," and she added the caption, "They never cease to amaze me - good thing I always pray for my enemies."

She later wrote on Twitter: "I have protected people over the evil things they have done - & I'm tired of it - tired of my parents living in denial. Time 2 tell the truth (sic)."

When one of her followers commented, "I just hope this isn't about your brother. He has a good side too (sic)," Stephanie responded, "No he doesn't."

Spencer, 33 - whose wife Heidi Montag is pregnant with the couple's first child - did not directly acknowledge the messages but later wrote on Twitter: "can't beef with peeps who have mental problems."

Stephanie, who stars in UK show 'Made In Chelsea', recently revealed Spencer never told her that Heidi is pregnant.

She said: "It was on my birthday and I literally just saw it on my phone. I was mad. I haven't spoken to him since.

"I have a feeling [my whole family] knew. I think I'm literally the only person who didn't. I just felt really left out. I don't feel part of my family."

However, Stephanie believes the pair will make great parents.

She added: "Heidi has wanted a kid for 10 years, she's born to be a mum. Spencer and I have nieces and nephews and he's very good with them.

"He always acts like he isn't interested but he's always got his phone out taking videos of them."