Police have arrested two Liberal Democrat members in Harrogate on suspicion of election offences.
It comes after the party wrongly claimed the Greens had stood down at a by-election.
A leaflet was distributed to households in March during the race to be the next councillor in the Stray, Woodlands and Hookstone division following the resignation of former Lib Dem Pat Marsh.
The leaflet urged voters to submit their postal votes before the deadline and described the race as being between the Liberal Democrats and the Conservatives.
It said Labour “came a distant third last time” and “the Green’s (sic) have stood down this election.”
The by-election was won in April by Lib Dem Andrew Timothy with 1,094 votes. He beat second-place Tory candidate John Ennis with 768 votes.
Gilly Charters represented the Greens and won 376 votes.
The Greens reacted angrily to the leaflet and submitted a formal complaint to the police who have been investigating if a crime had been committed.
North Yorkshire Police confirmed that two men were arrested on Tuesday in connection with its investigation. They have been released whilst enquiries continue.
A police spokesperson said: “A man aged in his 60s and a man aged in his 20s, both from the Harrogate area, were arrested on Tuesday 4 June in connection with an ongoing local election-related investigation.
“Following questioning, they have been released under investigation while enquiries continue.”
A spokesperson for the Liberal Democrats confirmed to the Local Democracy Reporting Service that the arrests were related to the by-election leaflet. They said the mistake was due to a printing error.
A Lib Dem spokesperson said: “This relates to a printing mistake during a local council by-election early this year, which we explained at the time.”