Ms Sheerin, from South London, was one of three party members questioned by Scotland Yard in March on suspicion of “publishing or distributing material likely to stir up racial hatred”.
Ms Murray was recently moved by Labour from her role as "stakeholder manager" to Leader of the Opposition, to provide support to the party’s complaints department.
Ms Murray and other staff were moved to help the department after it was reported that Thomas Gardiner, a Corbyn ally and powerful chief of Labour’s governance and legal unit, argued against suspending a Labour activist who posted an image on Facebook showing the Statue of Liberty being smothered by an alien with the Star of David on its back.
Mr Gardiner advised Ms Bibby not be suspended because the picture was “anti-Israel, not anti-Jewish.”
The party advertised the Head of Complaints role shortly after this.
Ms Murry is also facing legal action from Countdown presenter Rachel Riley, who instructed a high-profile lawyer after Ms Murray said Ms Riley had claimed: “Corbyn deserves to be violently attacked because he is a Nazi.”
"We don't comment on staffing matters," a Labour spokesperson said.
But a party source said: "Our recruitment processes are open, fair and designed to find the best person for the job, and that's what happened in this case."
