BusinessDay has also learnt that although the dead are receiving correspondence as part of the remediation effort, some living clients who are in dispute with Macquarie have yet to receive the letter that is required to be mailed out as part of a deal with the corporate regulator.

A BusinessDay investigation last month exposed allegations of serious problems at Macquarie Private Wealth (MPW), including an allegation that some advisers circulated a cheat sheet dubbed the "Penske file".

It followed a Senate inquiry that recommended the Australian Securities and Investments Commission (ASIC) put MPW under intensive surveillance.

Documents seen by BusinessDay show that ASIC is stepping in to investigate individual cases where Macquarie has spent months dealing with a complaint, but failed to finalise a response.

They paint a picture of its private wealth division that is plagued by incompatible computer systems, poor record keeping and advice documentation, and an inability to keep track of the sometimes complex financial products sold to clients by advisers.

It is understood that the level of documentation stored electronically has improved, but there are still inconsistencies and some of the files continue to have insufficient client information. "This isn't good enough for such a big organisation with highly paid brokers and ASIC monitoring them," an industry source said.

Macquarie said it was spending $49 million on "new processes, practices and systems over two years", relating to both the problems in its financial advice division and the implementation of new Future of Financial Advice laws.

"This includes new and enhanced technology to support the supervision and training of advisers," a spokeswoman said.

She said Macquarie's mailout was "largely complete".

In August MPW sent a letter as part of its mailout  to a man who died six years ago.

His daughter, who asked not to be named, said she received the letter last month. She said her father had a cash management trust, and when he died MPW received a death certificate and probate was granted.

"To me it says it is a sloppy process," she said. "They have obviously not cross-referenced the files to see if people are alive or dead."

She said sending letters out to dead people could cause distress to some people.

Macquarie's spokeswoman said: "Given the breadth of this communication and that it involves past clients from up to 10 years ago, there may unfortunately be isolated instances where this has occurred. We have received one complaint."

In another case, that of Don Waller, MPW only responded to his complaint after an article in BusinessDay last month exposed a 15-month delay. Financial services providers are required to respond to complaints within 45 days.

Mr Waller invested his $3.2 million in life savings with MPW in 2005 and lost more than half of it due to advice he believes was a "breach of contract" and negligent. He first wrote to Macquarie on May 31, 2013, requesting a review of his file with a view to getting financial compensation for the losses.

He said he finally received a response from MPW this month. "After the publicity they came back to me after almost 450 days, rather than the 45 days it should have taken them to respond," he said. Mr Waller said he was in the process of preparing a response. He declined to discuss the contents of MPW's letter.

In correspondence with a third client, sent in February, a compliance manager apologised that MPW would not be able to meet the 45-day deadline for a complaint lodged before Christmas.

The manager said delays were due to a high number of complaints received over an extended period of time.

By late May, MPW had yet to respond to the complaint, and the person looking after the file had changed twice.

The following month, MPW wrote to the client, saying it was still investigating the complaint. It took issue with the losses claimed, which the client said were based on records provided by Macquarie.

The client's lawyers wrote to ASIC, raising concerns that MPW's six-month delay in responding to the complaint might be a deliberate attempt to run out the clock by exhausting the period in which the client would be able to sue MPW.

Macquarie eventually provided a formal response in July, in which it said the client was not entitled to any compensation.

A Macquarie spokeswoman said: "Macquarie is processing all complaints as expeditiously as possible. We totally reject any suggestion of intentionally delaying the resolution of any matters."

ASIC in August assigned an investigator from its financial advisers team to raise the client's concerns with MPW.

ASIC has said there had been an improvement in the standards of record keeping over the course of the two-year enforceable undertaking it entered with Macquarie in January 2013. However, it is believed the problems with missing documents and inadequate records of advice still persist.

It is believed that ASIC is aware of client files that do not have enough information in them to meet the best interests' duty required under the law.

It is believed there were challenges gaining access to Macquarie's systems because there were so many, Wi-Fi was intermittent and shared IRESS access caused issues. Obtaining an active list of clients also proved difficult.