The art director Morris and copywriter Sinclair were hired by TBWA in June 2001 from BMP as creative partners and group heads. They were given final sign-off on creative projects by TBWA's creative director and chairman, Trevor Beattie, and were granted a roaming role throughout the department to cherry-pick accounts on which they wanted to work.
However it is thought the arrangement was ultimately mutually unsatisfactory.
It is unclear whether their free-roaming remit will fall to another of TBWA's key teams.
The team had worked at the agency in the 90s and created the BTAA gold-winning "double life" spot for the Sony PlayStation.
Morris and Sinclair's move to TBWA last year was a blow to BMP, which considered the duo to be a star team in its creative department. They won a gold award at Campaign's Poster Awards in 2001 for their VW "lost dog" ad.
Their stint at BMP was also relatively short-lived - they joined in March 2000 from Bartle Bogle Hegarty. While at the agency, they created campaigns for Levi's and One2One.
TBWA, Morris and Sinclair declined to comment as Campaign went to press.