UPDATE: Microsoft has told VideoGamer.com that Tesco's listing is bogus.
"This listing is not indicative of a Halo product launch," Microsoft said in a statement this afternoon. "We have no news to share of future Halo titles."
ORIGINAL STORY: Blowing the lid on Call of Duty: Ghosts may not be the only blunder from Tesco today.
An unannounced Halo title has also appeared on the retailer's website, suggesting that a new game in the sci-fi shooter series may be headed to Xbox 360 later in the year.
'Upcoming Halo' has been listed on the site, along with a generic Xbox 360 box art and (presumably) placeholder December 31, 2013 date.
Microsoft has yet to announce a future Halo title.
The most recent game in the series, Halo 4, launched last November.
Source: Tesco Direct