The actor's character Ryan Malloy is to have a "dramatic" exit storyline which will air later in the year, the Daily Star Sunday reports.
An EastEnders spokesperson told the newspaper: "We can confirm Neil is leaving EastEnders. It was a mutual decision that was made before Christmas when Neil's contract came up for renewal and we wish him all the best for the future.
"His exit storyline will be dramatic and fans will not be disappointed."
Full details of Ryan's departure are being kept under wraps, but it is thought that it could involve his upcoming animosity with evil pimp Rob Grayson, who used the barman's half-sister Whitney Dean (Shona McGarty) for his own financial gain in a sex exploitation storyline.
Earlier this month, McDermott and Jody Latham, who plays Rob, filmed climactic showdown scenes on location in Southend, Essex. Reports today suggest that both characters may be left in jeopardy following the clash.
"The scenes are going to be explosive. The fight ends with a dramatic cliffhanger where viewers will be left wondering if either of them survives," an insider told the tabloid.
McDermott joined EastEnders in early 2009 and his most memorable storyline saw Ryan at the centre of a love triangle involving his scheming wife Janine and fan favourite Stacey Branning. The plot culminated in Stacey's departure in 2010's Christmas Day episode.
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