The Scottish Liberal Democrats and SNP spent more than £160,000 on election expenses during the Shetland by-election.
The bulk of the £163,492 spent by the two parties came from the SNP, which had expenses approaching the £100,000 limit for a by-election (£98,958.48).
This compares to the Lib Dems, who spent £64,533.95 running their campaign, which saw their candidate Beatrice Wishart returned as MSP after the August vote.
In a by-election widely seen as a two-horse race, these amounts dwarf those incurred by other parties and candidates, including mainstream parties such as Scottish Labour and the Conservative and Unionist Party.
Labour spent £4,088.07, while the Conservatives’ expenses were more than four times this at £18,262.81.
Ukip’s expenses totalled £1,985.29 and the Scottish Greens’ campaign cost £1,441.77.
While the SNP spent the most of any party or candidate, independent candidate Ryan Thomson, who polled third, had the second lowest expenses at only £82.04, all spent on advertising.
Election expenses, which parties and candidates running in by-elections have to declare, are made up of advertising, unsolicited material, transport, public meetings, agents and other staff costs and accommodation and administration.
Candidates who took part in the August by-election included Johan Adamson, Scottish Labour; Brydon Goodlad, Scottish Conservative; Stuart Martin, Ukip; Debra Nicolson, Scottish Green; Ian Scott, Independent; Michael Stout, Independent; Peter Tait, Independent; Ryan Thomson; Independent; Tom Wills, SNP; Beatrice Wishart, Scottish Liberal Democrats.