Image copyright AFP PHOTO / KALLINEN LAW PLCC/HANDOUT Image caption The 13-year-old felt "extremely degraded" after the incident, the lawsuit says

Parents of a teenager who had his hair style filled in with a black marker pen have filed a civil rights suit against the Texas school district.

In April, a 13-year-old identified as JT came to Berry Miller Junior High School with an M shaved on his head.

The school principal, along with two colleagues, "took the jet-black Sharpie and started colouring JT's scalp" without his consent, the suit says.

The haircut allegedly violated the school's dress code policy.

At the time, according to CBS News, the code mandated that hair "must be neat, clean and well-groomed. Extreme hair styles such as carvings, mohawks, spikes, etc. are not allowed".

But the lawsuit says that the teenager felt "extremely degraded" after the incident, which it alleges was racist.

"The haircut did not depict anything violent, gang-related, obscene or otherwise offensive or inappropriate in any manner," the suit reportedly says, noting that a fade haircut "is common with African American youth".

JT's parents have filed their complaint against Pearland Independent School District, as well as Principal Tony Barcelona, disciple clerk Helen Day and teacher Jeanette Peterson.

All three school officials allegedly laughed as they used the permanent marker to colour JT's scalp.

But the lawsuit notes that the pen "made the design more prominent", and says his parents would have had the haircut changed had they been notified.

Pearland Independent School District altered their dress code policy in May.

Earlier in August, in nearby Galveston, police apologised after officers on horseback led a handcuffed black man by a rope, which many decried as reminiscent of the slavery era.