A teacher has been arrested for sending sexually explicit messages to a 15-year-old boy she met over Xbox One.

Robin Dunlap, 27, continued to exchange sexual messages with the boy even after learning his age, police said.

The boy, from Texas, presented himself as a 19-year-old throughout conversations with the science teacher, who worked at Haines City High School in Florida.

Their conversations moved to instant messenger and video calls.

When the mother of the victim checked her son's phone, she contacted Dunlap to inform the teacher her son was 15, not 19.

Dunlap voluntarily turned herself in to police and admitted she had sent nude photos to the boy before learning his real age.

"But it didn't stop there," the press release from Winter Haven police said.

Robin Dunlap continued to exchange sexual messages with the boy even after learning his age (Winter Haven Police)

Dunlap continued to contact the boy through Google Hangouts and would later tell police the teenager was the only person who understood her.

The teacher gave police access to her phone, where they found conversations which "slowly to extremely vulgar with sexually explicit language," according to the release.

“There is absolutely no excuse for an adult – especially a high school teacher – to continue sexually explicit conversations with a 15 year-old long after his real age is revealed,” Winter Haven Police Chief Charlie Bird said.