The Scottish Liberal Democrats have been fined £500 for failing to deliver accurate spending returns in the 2016 Scottish Parliament election.

The Electoral Commission launched an investigation earlier this year following a complaint.

The party had previously said there was no substance to the claim, with national leader Sir Vince Cable describing it as “mischief”.

Bob Posner, director of political finance and regulation at the Electoral Commission, said: “Political parties and campaigners must provide accurate and transparent spending returns so that they can be scrutinised by voters.

“In this case, the party aggregated some payments rather than declaring each payment individually as required by the law. As a result it was not possible to identify some of them, resulting in less transparency.”

A spokesman for the Scottish Liberal Democrats, who paid the fine last week, said: “This is a small penalty for a technical fault on the declaration of our election returns.

“All funds were accounted for but they should have been disaggregated.”