One Direction have given the biggest hint to date that they're set to reunite with Zayn Malik.

The Pillowtalk hitmaker was an original member of the group from 2010 to 2015, when he sensationally quit the band and went solo, leaving Harry Styles, Louis Tomlinson, Liam Payne, and Niall Horan to continue as a four-piece.

The singers have made no secret of their subsequent feud with Zayn, with Niall recently commenting that the 27-year-old "never really spoke to" the group after walking away from the spotlight.

However, eagle-eyed fans have spotted a development in their relationship, as all four members of the group are now once again following Zayn on Twitter. In addition, the official One Direction account has been reactivated.

Posting with the hashtag #OneDirectionReunion, fans also spotted the group's imagery on Apple Music had been amended to include Zayn.

During a recent interview, Liam hinted at a forthcoming reunion - though he didn't name his former bandmate as part of the plans.

"We've all been speaking together a lot over the last few weeks, which has been really nice," he stated. "To hear a lot of people's voices and seeing old content and different things that we haven't seen for a long time or never seen before, it's very interesting... More than anything it's just been a real good time for us to connect together again."

One Direction rose to fame on U.K. TV talent show The X Factor in 2010, and topped charts worldwide with hits including What Makes You Beautiful, Night Changes, History, and Story of My Life.