EASTENDERS has revealed Teddy Mitchell’s dark side – as his killer secret is exposed.

The character – played by Roland Manookian – first arrived in Walford last year.

Teddy was devastated to learn about Sharon’s (Letitia Dean) infidelity with Grant (Ross Kemp).

Sharon explained it had been a mistake and she’d been “vulnerable” after Martin’s (James Bye) death.

Teddy was furious and a huge row soon escalated between him and Sharon.

Sharon told him: “Do you want the truth, Teddy? I’m not ready for this.

“I’m not over Keanu, I never was. I threw myself into this thinking that I would be eventually, but I’m not.

“Teddy, you really are a great bloke but it just moved too fast, okay? I didn’t want to be alone.

“I needed a friend. And if you’re honest, maybe you’re not over Nicola too.”

This particular remark saw Teddy turn violent and smash a glass onto the floor.

Zack (James Farrar) and Nicola (Laura Doddington) arrived, as Teddy yelled for everyone to get out.

Coming face-to-face with Teddy, Zack told him: “You walk around like you’re a nice guy, saying all the right things.

Watch the moment Sharon Watts cheats on Teddy Mitchell with ex-Grant as former couple share passionate clinch

“But this is really you, isn’t it? You’re just a bully.”

Their confrontation saw Teddy snap and brutally beat Zack – only stopping when Barney appeared in the doorway.

It comes as Teddy remains unaware that Zack is Barney’s biological father.

Later, Zack threatened to tell Barney the truth – and go the police – but Nicola dropped a huge bombshell about Teddy

She mentioned Harry’s ex-girlfriend Shireen Bashar, who disappeared years ago.

Nicola told them: “Teddy Mitchell is a killer. And if you take his son away, he will kill you. And me.

“He won’t lose a wink of sleep over it. He slept soundly next to me for years.”

She added: “Shireen Bashar. Look her up and then keep your mouth shut, for all our sakes.”