Google’s weekly transparency reports contain updates on how much money has been spent by political parties and other organisations on advertising.

A transparency report published this week claimed the Labour Party had spent £50 on adverts during the week the general election was called, and nothing the week after. However, according to figures disclosed by Google in a previous report seen by the Guardian, Labour spent £63,900 during that fortnight.

There was also a similar but smaller discrepancy in the reporting of spend for the Conservatives.

The Guardian reported Google admitted that the most recent report was incorrect when the paper highlighted the discrepancy.

A Google spokesperson said: “We are looking into this issue. If we find any ads that were mistakenly underreported, we will add them into our transparency report as soon as possible.”