Former homicide squad boss Sol Solomon sent Victoria Police his statement in January and asked it be passed to the commission, but it was only received in May, and not from police.

The high-profile commission is looking at the recruitment and management of people used to supply information to police, including gangland barrister Nicola Gobbo, also known as Lawyer X.

Commissioner Margaret McMurdo suggested the long-awaited document did not infer police wanted it buried.

Lawyer for the police, Renee Enbom, strenuously denied any reluctance on the part of the force, but was ordered to provide an explanation.

She updated the commissioner on Wednesday, saying the officer who received the statement had his attention elsewhere.

"(He was) focused on other issues and having to attend to an enormous number of tasks and not giving that statement the attention it deserved when it came in," she said.

He "put things in motion" to provide the statement in early May after being reminded of it.

But counsel assisting the commission, Chris Winneke, noted the document was received from another source on May 15 and the police copy never arrived.

Mr Solomon's statement refers to his interactions with Ms Gobbo when he was investigating the execution-style gangland murders of police informers Terence and Christine Hodson in 2004.

He's expected to give evidence in future hearings.

Lawyer Daniel Marquet, a partner at Corrs Chambers Westgarth - the firm representing police - apologised in a letter further outlining the oversight.

"At the outset, we wish to assure you that Victoria Police did not seek to conceal Mr Solomon's statement from the royal commission," he wrote.

The force's objective was to provide full assistance to the commission and had dedicated significant resources to doing so, he added.

"The task is complex and the workload is overwhelming," he wrote.

Ms McMurdo appeared to reluctantly accept the response.

She has asked for an audit of submissions to ensure there are no other missing statements.

Commission hearings are set to resume on June 17 with evidence from controversial former drug squad detective Paul Dale.

Australian Associated Press