A lawyer who admits ripping off elderly clients for millions of dollars will be sentenced in Christchurch today.

John Milne pleaded guilty last month to 34 charges of misappropriation and theft by a person in a special relationship.

The 79-year-old elicited money from clients and associates on the premise that he would invest that money and pay them a return.

None of that money was ever invested, with monies from later clients used to pay earlier investors.

Milne stole close to $3 million over a 20-year-period, with the Serious Fraud Office saying this actions had all the hallmarks of a Ponzi scheme.