Commonwealth Bank chief executive Matt Comyn has drawn howls of laughter as he tried to answer questions during an interrogation at the hands of House of Representative MPs.

In a gruelling and at times hostile hearing on Thursday morning, Mr Comyn was grilled by the standing committee on economics on a range of issues, including those unearthed by the financial services royal commission.

But, despite the seriousness of the issues, Mr Comyn’s answers to many of the committee’s questions were met with laughter and heckling from a bemused audience in the public gallery.

This was most evident when Mr Comyn was asked whether the Commonwealth Bank really needed a royal commission to demonstrate why charging deceased Australians was inappropriate – to which Mr Comyn gave a curt “no”.

Labor’s financial services spokeswoman, Clare O’Neil, asked about fees charged to dead people, pointing to a media release from the Australian Bankers Association. Issued on Wednesday, it implied “the expectation of accolades” for agreeing to remove the fees, she said.

“Why the press release and the fanfare yesterday?” Ms O’Neil said. “Are we really at the point where the code of conduct is just saying that banks need to follow the law?”

Mr Comyn – who took up the top job at the CBA six months ago – was also taken to task for not meeting face-to-face with customers who had suffered as a result of misconduct or negligence. He told the committee he had so far met “less than 10” affected customers.

“I certainly acknowledge the hurt and the very, very difficult circumstances that some of our customers have found themselves in, and some of that as a result of our actions,” he said.

Ms O’Neil’s pointed line of questioning brought a round of applause as the hearing broke for a tea break.

But it was a question from deputy chair, Labor MP Matt Thistlethwaite, that really put the pressure on Mr Comyn. He asked about Commonwealth Bank staff tampering with Youthsaver accounts.

In late 2012, some staff deposited spare change from a bank branch into these accounts, without the knowledge of the young account owners or their parents. The deposits “activated” the accounts, putting the staff member responsible in line for a bonus.

At the time, Mr Comyn was the CBA’s head of retail banking. He was involved in a 2016 investigation by law firm MinterEllison into the issue, and was still being investigated in February this year when he was appointed as to the bank’s top job.

Mr Comyn said he “proactively” brought the investigation up at his interviews for the head role. The MinterEllison review had looked into a broader range of issues than Mr Thistlethwaite had been made aware of, he said.

He offered to discuss the issue in more detail after the hearings.

Mr Comyn earlier admitted the CBA was too slow to fix customer service problems uncovered by the banking royal commission because it had become complacent.

“There have unfortunately been failures of judgment, failures of process, failures of leadership, and in some instances, greed,” he said.

“We’ve been too slow to identify problems, too slow to fix underlying issues, and too slow to put things right for customers.”

The hearing is being held by the House of Representatives committee on economics as part of a review into the big four banks.

Westpac CEO Brian Hartzer will also front the hearing on Thursday.

ANZ chief executive Shayne Elliott will appear on Friday and National Australia Bank boss Andrew Thorburn will appear next week.

-with AAP