A Cricket Australia (CA) investigation of Moeen Ali's allegation of a racial slur from an Australian player during the 2015 Ashes series has found no evidence for further pursuit of the claim.

In an extract from his new book, Moeen stated that an Australian player had called him "Osama" during the first Test of the series, in Cardiff, and that he had told the England coach Trevor Bayliss, who then raised the matter with Australia's then coach Darren Lehmann. However, the unnamed player involved denied the allegation, claiming he had called Moeen a "part-timer".

When Moeen's account of events came to light, CA indicated that the governing body was in touch with the ECB, and that a further investigation would take place. The CA integrity unit, until recently headed by Iain Roy but now helmed by Sean Carroll, subsequently interviewed numerous Australian players from the 2015 Cardiff Test and team management, while also communicating with the ECB's own integrity unit.

The investigation concluded on the weekend, and it is understood that no other player said they heard the alleged remark. "We have followed up with the ECB and our team management and confirmed that the incident was investigated at the time, with a response provided to Moeen," A CA spokesman said.

"Moeen elected not to progress the matter any further and we have not been able to ascertain any new additional evidence through our enquiries. As such, the matter is considered closed. We take a zero-tolerance approach to remarks of this nature; they have no place in our sport, or in society and any allegations raised with us are treated seriously and respectfully.

"Representatives of our country are expected to uphold a high standard of behaviours and values, and they are fully aware of the consequences should they fail to do this."

Bayliss has said that Moeen did not want the matter to be taken further, a process that would have involved the ICC and the racial vilification clauses of its code of conduct. "He didn't want it to go any further. He was happy for it [to be dealt with between the two teams]," Bayliss told News Corporation. "He's a very softly-spoken sort of a bloke. He doesn't want to create too many problems for anyone.

"I'm not going to make too much of it, it was bloody three years ago, let's move on. [Cricket Australia] can do what they like I suppose, everyone has sort of forgotten about it and moved on since then. I don't see it as any real big deal. It was a hard-fought series. But no, I thought [relations after that point] were OK. You're not party to what goes on out on the field and certainly nothing else was reported or anything through that series so we just left it at that."

Under the CA code of conduct, the governing body would have had the option of re-opening the matter and laying a charge if new evidence had been found by the integrity unit.

Meanwhile, CA's own cultural reviews are believed to be in their closing stages, with the report on the organisation's wider operations submitted by Simon Longstaff, the director of the Ethics Centre and has been viewed by the directors of the governing body's Board. This review of the organisation is expected to be made public. According to the reviews' terms of reference:

"The first, overarching independent review will investigate whether any wider cultural, organisational and/or governance issues within CA, and more broadly within Australian cricket, should be addressed to ensure these events never occur again, either on tour or whilst playing in Australia. This review will investigate links between player behaviour (particularly on this tour of South Africa) and the organisational, governance and culture within CA and Australian cricket.

"The separate player review will, in consultation with a small panel of current and past players, consider a behavioural Charter for the Australian men's cricket teams that balances the performance demands of elite cricket with expectations of all Australians in regard to on- and off-field role modelling.

"It is expected that at various stages the findings from this Wider Cultural, Organisational &/or Governance review will cross-check with the work of the panel that is exploring a Charter for the Australian men's team - and, where appropriate, incorporate any findings or relevant information into its work."

The review of the Australian men's team, conducted by the former Test opener Rick McCosker, is set to be submitted shortly, with a concurrent drafting of a charter for player behaviour also near to completion, as indicated by the national team captain Tim Paine before his departure for the tour of the UAE to play Pakistan last week.

"Cricket Australia has committed to sharing the findings from the concurrent reviews before the season begins," a CA spokesman said. "There are still a number of steps to be taken before the process is complete. At such time, we will engage key stakeholders, among them the media. It would be inappropriate to comment on speculation or provide a running commentary while the process is ongoing."