England have revealed that Joe Marler has apologised to Samson Lee for verbally abusing the Wales prop in Saturday's 25-21 Six Nations victory at Twickenham.

Tournament organisers have confirmed they are investigating an incident in the first-half in which Lee can be heard on referee Craig Joubert’s microphone being called a “gypsy boy”.

Angered by the insult, Lee squared off with Marler and a statement released by the Rugby Football Union on Sunday afternoon confirmed the Harlequins loosehead was responsible for the remark.

"Joe spoke to Samson at half-time to apologise and he was reminded by (head coach) Eddie Jones of his responsibilities as an England player after the game," the RFU statement read.

Verbal abuse of a player based on religion, race, colour, national or ethnic origin, sexual orientation or otherwise carries a minimum sanction of a four-week suspension.

Marler’s admission of guilt thus effectively signals the end of his Six Nations as England are seeking to complete the Grand Slam in their final match of the Championship against France in Paris on Saturday.

Adding to Marler's woes in an eventful first half for the Harlequins front row is an incident in which he appeared to land a forearm in the face of Wales prop Rob Evans, an offence which carries an entry-point sanction of two weeks.

“We are aware of the incidents and are establishing the facts at this moment,” a Six Nations spokesperson said.