Jeremy Renner has revealed that he is slipping into his Hawkeye costume again for a new Marvel project - but he's staying tight-lipped about what it is.

The 44-year-old actor took to his WhoSay page to share an arty silhouette drawing of his Avengers character.

[related]He wrote: "Tues morn. I find myself in costume again, I just can't tell you why. And it still fits!"

Tongues have obviously been set wagging by the teaser - with two theories coming to the fore.

The first is that he's getting back into character for re-shoots on Avengers: Age Of Ultron.

Although filming wrapped on the Joss Whedon movie last year, it has previously been reported that additional scenes could be needed and that January was the time it would happen.

The other suggestion is that he's going to pop up in ABC TV series Agents Of S.H.I.E.L.D - which has previously teased a link to the Avengers sequel.