England fast bowler Ollie Robinson issued an apology after historic messages of a racist and sexist nature posted on his Twitter account emerged on the day of his Test debut.

Robinson took 2-50 on the opening day of the first Test against New Zealand, who reached stumps on 246-3 at Lord's.

However, while the Sussex seamer was in action on the field, comments he made in 2012 and 2013 – when he was aged 18 and 19 – emerged on social media.

In a statement published by the England and Wales Cricket Board (ECB) at the close of play, Robinson admitted to being "embarrassed" and "ashamed" at the social media posts.

"On the biggest day of my career so far, I am embarrassed by the racist and sexist tweets that I posted over eight years ago, which have today become public," he said.

"I want to make it clear that I'm not racist and I'm not sexist. I deeply regret my actions, and I am ashamed of making such remarks. 

"I was thoughtless and irresponsible, and regardless of my state of mind at the time, my actions were inexcusable. Since that period, I have matured as a person and fully regret the tweets.

"Today should be about my efforts on the field and the pride of making my Test debut for England, but my thoughtless behaviour in the past has tarnished this.

"Over the past few years, I have worked hard to turn my life around. I have considerably matured as an adult. 

"The work and education I have gained personally from the PCA (Professional Cricketers' Association), my county Sussex and the England cricket team have helped me to come to terms and gain a deep understanding of being a responsible professional cricketer.

"I would like to unreservedly apologise to anyone I have offended, my team-mates and the game as a whole in what has been a day of action and awareness in combatting discrimination from our sport. 

"I don't want something that happened eight years ago to diminish the efforts of my team-mates and the ECB as they continue to build meaningful action with their comprehensive initiatives and efforts, which I fully endorse and support.

"I will continue to educate myself, look for advice and work with the support network that is available to me to learn more about getting better in this area. I am sorry, and I have certainly learned my lesson today."

The discovery of the comments came after England's players wore anti-discrimination T-shirts carrying messages regarding racism, sexism, transphobia, homophobia and ageism ahead of play starting on Wednesday.

ECB chief executive Tom Harrison strongly condemned the posts and confirmed a full investigation will be launched as part of the governing body's disciplinary process.

"I do not have the words to express how disappointed I am that an England men's player has chosen to write tweets of this nature, however long ago that might have been," Harrison said in a statement.

"Any person reading those words, particularly a woman or person of colour, would take away an image of cricket and cricketers that is completely unacceptable. We are better than this. 

"We have a zero-tolerance stance to any form of discrimination and there are rules in place that handle conduct of this nature. We will initiate a full investigation as part of our disciplinary process. 

"Our England men's team, alongside others from the ECB and our partners across the game, worked together today to create a moment of unity. 

"Using today's spotlight to reaffirm our commitment to driving forward an anti-discrimination agenda. 

"Our commitment to that effort remains unwavering, and the emergence of these comments from Ollie's past reiterates the need for ongoing education and engagement on this issue."

Robinson dismissed Tom Latham and Ross Taylor but New Zealand debutant Devon Conway scored an unbeaten century to leave the tourists in control.