A parliamentary watchdog has dropped an investigation into the expenses of Scotland's First Minister, Henry McLeish, because he is no longer an MP.

Westminster's parliamentary standards commissioner, Elizabeth Filkin, had begun making inquiries into claims that the Scottish Labour leader was "slow" to declare money he received for subletting part of his constituency office at Glenrothes in Fife.

But because Mr McLeish stood down as the Member of Parliament for Central Fife to concentrate on his work as a Member of the Scottish Parliament, he is no longer subject to the scrutiny of the commissioner, whose remit only extends to Westminster parliamentarians.

Mrs Filkin had begun making early inquiries after claims that Mr McLeish was slow in declaring �4,000 received for subletting part of his constituency office to a legal firm.

Elizabeth Filkin decided to drop the inquiry

The First Minister eventually lodged the payment in the register of interests, but it was alleged he had broken strict guidelines.

Mrs Filkin's office has confirmed the matter is at an end now that Mr McLeish is no longer an MP.

A spokeswoman for Mrs Filkin said: "Under the procedures, the commissioner often has to make preliminary inquiries to establish whether or not she is going to carry out an investigation.

"At that point, it is not yet clearly known whether an investigation is warranted.

"At the point at which she was making those preliminary inquiries, the time came for the general election.

"And her remit only extends to MPs."

Opposition politicians have reacted to the move with surprise.

Alex Salmond, leader of the Scottish National Party group at Westminster, said: "Henry McLeish is going to have a cloud hanging over him if these extremely serious allegations of misusing public funds are not properly investigated.

"I would have thought that the First Minister would demand the opportunity to clear his name, but he clearly has no intention of doing so."

The Conservative's shadow Scottish secretary, Dominic Grieve, said: "I am very surprised.

"I don't see why somebody ceasing to be an MP makes their actions cease to be a matter for the commissioner."