Billy Mitchell (EastEnders) revealed in 2006 that the role was extended by "coincidence and chance": "I was offered four episodes and here I am, about 800 later. [...] Ross Kemp (Grant) said that he was leaving, and there was a gap in the Mitchell family, so they brought me back to do stuff towards his leaving. After that they offered me a year." Billy was reintroduced in 1999, making recurring appearances. He was involved in the leaving storyline of Grant Mitchell in October 1999, before returning later in the year as a regular character. When Billy was first introduced, he was depicted as
Ross Kemp Watts (Letitia Dean) and Tiffany Mitchell (Martine McCutcheon), as well as the "Sharongate" storyline, which saw brother Phil Mitchell (Steve McFadden) having an affair with Grant's wife. Kemp announced in April 1999 that he would be leaving the soap later that year after nearly a decade. His exit was aired in October 1999 when his character moved to Brazil after surviving a car crash. Kemp refused to rule out an eventual return to "EastEnders", and various media reports over the next few years speculated that he would return to the series at some stage. In early 2005, the BBC confirmed