Cops are investigating the finances of a smear group that claims missing Madeleine McCann is dead.

Detectives are probing claims the boss of the Madeleine Foundation pocketed up to £90,000 of donations from people who thought they were helping the official Find Madeleine Fund.

Retired solicitor Tony Bennett, 62, runs the group from his home in Harlow, Essex.

And much of the cash under investigation comes from sales of a book he wrote blaming Maddie's parents Kate and Gerry for the three year-old's disappearance. All his group's accounts have now been frozen.

A McCann spokesman said last night: "It has been made clear to Mr Bennett by Kate and Gerry's lawyers that he must desist from his defamatory activities."

Meanwhile the McCanns, of Rothley, Leics, are drip-feeding their four-year-old twins information on Madeleine as they grow up.

Gp Kate, 41, said child psychologists have advised them Sean and Amelie will question them about their sister when they feel ready.

She added: "If they ask a question, we'll answer them honestly. But I'm not going to rush them."

Maddie vanished her parents' holiday flat in Praia da Luz, Portugal, in May 2007.

Kate said: "All we want to do is find her - and the only way we can do that is by looking forward."