Marvel's Black Panther: Who Is the Black Panther? motion comic has mysteriously disappeared from iTunes, the PlayStation Network and other outlets after just three episodes. It's also been removed from the motion comics section of the publisher's website, which now only features listings for Iron Man: Extremis, Astonishing X-Men: Gifted and Spider-Woman.

Marvel declined comment. However, there's speculation the company may not have had the rights to digitally distribute the 12-episode Who Is the Black Panther?, which was produced in partnership with BET Networks.

Announced in April 2008 as an animated adaptation of the story arc by Reginald Hudlin and John Romita Jr., Who Is the Black Panther? was set to debut on BET in early 2009. Despite boasting an all-star cast that includes Djimon Hounsou, Jill Scott, Kerry Washington, Alfre Woodard and Stan Lee, the series never aired on BET. It had its world premiere in January 2010 on Australia's ABC 3.

The project had seemingly fallen off the map until last month, when Marvel announced the release of Who Is the Black Panther? as a motion comic under its Marvel Knights Animation banner. The series was heavily promoted online and with ads in Marvel comics.

The first episode debuted on June 23 on iTunes, Xbox LIVE, Microsoft Zune and the PlayStation Network, with new installments promised weekly. However, the fourth episode, which should've been released last Wednesday, never materialized.