Jeremy Corbyn has privately expressed concern that evidence of anti-Semitism within Labour was “mislaid or ignored”, leaked recordings suggest.
The Sunday Times has released part of a conversation the party leader had with Dame Margaret Hodge, which she taped.
The Barking MP has been a fierce critic of Mr Corbyn’s stance on anti-Semitism.
A Labour spokesman said the tape showed Mr Corbyn’s desire for “robust and efficient” procedures and to “rebuild trust with the Jewish community”.
Throughout much of his leadership, Mr Corbyn has been dogged by criticism from within the party about his handling of anti-Semitism claims.
Last year he became embroiled in a row with Dame Margaret over the issue, which saw the party launch – and then drop – disciplinary action against the long-serving Jewish MP.
She secretly recorded a conversation between the pair in February, as Mr Corbyn talked over a plan to recruit former cabinet minister Lord Falconer to review the party’s complaints process.
“Just to reassure you, he’s not going to be running the system; he’s not entitled to do that,” the Labour leader says on the tape, which was given to the Sunday Times.
“He will look at the speed of dealing with cases, the administration of them and the collation of the evidence before it’s put before appropriate panels… because I was concerned that it was either being mislaid, ignored or not used, and there had to be some better system.”
In March, Dame Margaret claimed Mr Corbyn had misled her – or been misled by his staff – over assurances the leader’s office was not involved in disciplinary procedures.
Labour dismissed the suggestion as “categorically untrue”.
Last week, the Jewish Labour Movement voted to pass a motion of no confidence in the Labour leader.
Its national secretary Peter Mason said reports of delays, inaction and interference from the leader’s office showed the party’s processes were “incapable of dealing with anti-Jewish racism”.
Dame Margaret is among seven Labour MPs to write to the Sunday Times this weekend, calling for a “fully independent body” to deal with complaints of racism, harassment and bullying.
They complain of “a growing backlog of unresolved cases of vile racism”.
“Despite telling us things are better, the party has clearly failed to get to grips with its anti-Semitism problem,” the letter says.
“The current complaints system is broken. There must be a real change at the top of the party.”
However, a Labour spokesman said: “The Labour Party takes all complaints of anti-Semitism extremely seriously and we are committed to challenging and campaigning against it in all its forms.
“All complaints about anti-Semitism are fully investigated in line with our rules and procedures and any appropriate disciplinary action is taken.”
A party source told the BBC that before Jennie Formby became general secretary a year ago, there had been concerns that Jewish activists not in breach of rules were targeted, while efforts to tackle clear cut cases of anti-Semitism were obstructed.