A Catholic school in Virginia is investigating after an image appearing to show a student in blackface alongside the N-word was posted on social media.

The racially offensive photo is believed to have been posted by a high school student in Richmond and showed a white female student in uniform.

Administrators at all girls St. Gertrude High School are probing allegations that the image posted showed a blackface mask with the 'N****' written underneath.

The girl in the image, which has been circulated on social media after initially being posted on Snapchat, appeared to be wearing school uniform.

Sister Cecilia Dwyer, the head administrator at St. Gertrude's Catholic School, said authorities were trying to work out the sequence of events that led up to the image being posted.

The image of a white female student appearing to pose with a blackface mask alongside the word 'N****' was initially posed on Snapchat

One former student alleged she was threatened with racist hate mail in a separate incident that was not investigate

She told NBC 12: 'It was a huge indiscretion on the part of a couple of students but it's one that we deeply regret and one we can't tolerate as part of our culture. It doesn't represent who we are.

'We're trying to untangle the knot of who did what and when and there will be consequences.'

On the day she learned about the post, the school sent a letter to parents saying: 'This morning we became aware of some deeply troubling and racially insensitive imagery making its way through our community.'

Students have said they know both the person who appeared in the image and another student who was also involved.

Former students have said they think the student involved should face being expelled form the all girl's school.

St. Gertrude High School, a Catholic all girl's school in Richmond, Virginia, is investigating the incident that saw a racially offensive image posted online

One ex-pupil said she received threatening and racist hate mail when she was a student at St. Gertrude that was not investigated.

Former student Taylor Moore told WTVR: 'It just shocks me that that was never my experience there and it's happening now is really disheartening.

'I think there's a valuable lesson that serious actions have serious consequences. I'm praying for the school and the administrator make the right decisions.'

JJ Minor with the Richmond NAACP said he had received more than 30 calls about the incident.

He said: 'I received over 30 phone calls about this incident, especially from some of the parents.

'Blackface has an evil history of mocking African-Americans. Whether they're children or not, they did it plain and simple. Someone taught them how to do it and folks know what Blackface means and it is offensive.'