Teen writes emotional letter to sister after discovering they aren't full siblings

Twitter users have been left in tears over a tweet containing an emotional letter a brother wrote his older sister after discovering they are not 'full' siblings.

18-year-old Pamela Lara from Houston, Texas (US), was so touched by her brother's note Jared Escamilla, 17, that she had to share it with the world, the Daily Mail reported.

In it he states: “I just wanted to let you know how much I love you. I don’t care what people say, you are always going to be my sister, my full blooded sister.”

“I will always be there for you just like you always have been there for me. I love you. With love, your annoying brother.”

He even presented her the letter with some of her favourite snacks.

After the heart breaking news, the family needed time to deal with the reality of the situation. While Pamela has known since she was nine that her brother and sister are her half-siblings, the revelation came as a shock to Jared who only just found out.

It is unclear how he found out about it. Pamela told PEOPLE that it had been a secret because she did not want to "be looked at differently by my siblings".

When Pamela posted a photo of the note on Twitter it viral and has garnered close to 52,000 likes. They have received a lot of support from kind strangers.

Here are some of the reactions: