Depp, 53, previously had a tattoo across the knuckles on his right hand which read "SLIM", a reported nickname for Heard who filed for divorce from Depp in late May and has since been granted a temporary restraining order against him following domestic violence allegations.

However, pictures taken in Pennsylvania on Friday, where Depp is touring with his band Hollywood Vampires, appear to show the "L" and the "I" of the tattoo have been redrawn as a "C" and "U", respectively, leaving the tattoo to read, "SCUM".

Depp's representatives are yet to comment on the tattoo adjustment.

Heard, 30, was granted a temporary restraining order against Depp five days after filing for divorce after the actress presented to the court with a bruised cheekbone and alleged Depp had committed acts of domestic violence. The matter will be heard in court in mid-August, with the possibility that the order will be removed or extended.

The origins of Heard's "Slim" nickname have never been confirmed by Heard or Depp.

However, it has been suggested by fans of the couple that the name is a reference to 1940s Hollywood actress Lauren Bacall (known for playing "Slim" against Humphrey Bogart's "Steve"), who Depp said Heard reminded him of in a 2011 USA Today interview promoting their film, The Rum Diary.

"When I first saw Amber, it was like seeing an old-time movie star," Depp said. "It was like I was seeing Lauren Bacall."

Depp and Heard met on the set of the film in 2009, however they did not begin dating until three years later, shortly after the end of Depp's marriage to Vanessa Paradis.

The tattoo was not Depp's only inking to bear Heard's alleged nickname.

He also has the words "Come with me... Slim" tattooed on his right elbow.

The elbow tattoo was first spotted at a press conference for the Lone Ranger in June 2013, after Depp and Heard had been dating for a year.

It is not known whether the elbow tattoo has also been altered.

The entire story comes with a sense of deja vu: in 1994, Depp altered a tattoo dedicated to his former flame Winona Ryder which read "Winona forever" to simply read "Wino forever" after the pair split.