PARLIAMENT'S sleaze watchdog announced on Tuesday that he would be investigating Meriden MP Caroline Spelman.
Standards Commissioner John Lyon confirmed he would be conducting a full inquiry into Mrs Spelman's use of expenses to pay her nanny.
It was thought unlikely that Mr Lyon would initiate a full investigation because the matter dated back to over seven years ago.
A storm erupted around Mrs Spelman earlier this month - when it emerged she had paid Tina Haynes to look after her children and do secretarial work.
Originally it was thought that Mrs Spelman, chairman of the Conservative Party, had only employed Ms Haynes for a short term period, but last weekend's Sunday Times published a story that suggested the nanny had remained on the public payroll for almost two years.
Mrs Spelman, who has insisted she did nothing wrong, had taken the unusual step of asking Mr Lyon to carry out an investigation into the claims she misused public funds.
A statement issued by Mr Lyon's office, said: "Having carefully considered the matter,
the Commissioner has recommended to the (Standards and Privileges) Committee that exceptionally he should conduct an inquiry. The Committee has accepted that recommendation."
He must now determine whether Mrs Spelman breached the rules of the House in force at the time.
A Conservative Party spokes-woman said Mrs Spelman could not comment on the matter while the standards commissioner was considering the case.