A lobbying firm made a donation to Labour's Holyrood election campaign, it has emerged.
The lobbyist arranged campaign visits for Jack McConnell
A professional lobbyist from Luther Pendragon worked for the Scottish Labour Party during the May election campaign while on a sabbatical.
He later returned to his job with the London-based firm.
The company has contacts with the Department of Trade and Industry and the Cabinet Office among many others.
The Conservatives have described the arrangement as "questionable".
The move appears in Labour's latest declaration to the Electoral Commission, reawakening the controversy over potential conflicts of interest.
Douglas Trainer, who was employed by the firm, Luther Pendragon, worked for the Labour Party's Scottish Parliament election campaign during April.
Mr Trainer is a partner in the company and a former Labour president of the National Union of Students.
The value of his time has been estimated at more than £4,000.
Labour said Mr Trainer arranged campaign visits for First Minister Jack McConnell during a sabbatical.
The Tories said the deal was "questionable", wondering what the payback might be.
Luther Pendragon's clients have included Westminster government departments and the billionaire Hinduja brothers.
The firm's lobbying arm claims success in influencing regulators and politicians.
Labour insists any impression of impropriety is false.