At almost 100 years of age Mavis Sherwin walked into her local bank branch to report she had lost her passbook.

She was shocked when she was told that more than $1 million had washed through her accounts without her being told.

Actor Peter Phelps and wife Donna. Phelps lost his superannuation through investing with Sherwin.

She also discovered that her bankrupt son, Bradley Sherwin, the 60-year old former head of Sherwin Financial and Wickham Securities, had opened a credit card in her name and set up an internet banking login so that he could use her accounts to squirrel money away.

"Mrs Sherwin confirmed with us that the funds credited to her passbook did not belong to her and that her son had arranged [for] the money to go into her passbook without her permission," the file note from the Commonwealth Bank reads, regarding Mrs Sherwin's visit to the Brisbane branch in October 2014.