Prince Harry's girlfriend Meghan Markle has been left with no choice but to "block and report" vicious trolls who send her vile racist messages online.

Meghan Markle

Meghan Markle

The brunette beauty - who has been dating the flame-haired prince for eight months - has penned a gut wrenching letter about the abuse she endured on social media over her role as Rachel Zane in US legal drama 'Suits'.

In the post, which she penned before she started romancing the prince, published via Elle magazine, Meghan said: "I remember the tweets when that first episode of the Zane family aired, they ran the gamut from: 'Why would they make her dad black? She's not black' to 'Ew, she's black? I used to think she was hot.' The latter was blocked and reported.

"The reaction was unexpected, but speaks of the undercurrent of racism that is so prevalent, especially within America."

The 35-year-old actress - whose father is Caucasian and mother is African-American - also recalled the moment she witnessed her mum Doria being called "the 'N' word" and when she was younger "being asked where my mother was since they assumed she was the nanny."

Although the letter was written before she started romancing Harry, Meghan was also bombarded with horrendous messages when the couple went public.

Shortly after their relationship was revealed six weeks ago, the 32-year-old royal released a statement claiming his lover had been on the receiving end of a "wave of abuse and harassment " including "outright sexism and racism."

The statement, released on his behalf by Kensington Palace, said: "Prince Harry is worried about Ms Markle's safety and is deeply disappointed that he has not been able to protect her. It is not right that a few months into a relationship with him that Ms Markle should be subjected to such a storm."