Led Zeppelin’s lawyers have requested a judge dismiss a copyright infringement case against them. The estate of Spirit founder Randy Wolfe, who was also known as Randy California, accused the band’s songwriters of copying a riff for Stairway to Heaven.

Singer Robert Plant and guitarist Jimmy Page, as well as Warner Music, argue that the estate of Wolfe failed to prove it owned the copyright to his 1968 song Taurus and that it was substantially similar to Zeppelin’s song, attorney Peter Anderson said. “Plaintiff rested and failed to carry his burden of proof on multiple issues,” Anderson wrote in a motion to dismiss.

US district judge R Gary Klausner is expected hear arguments on the motion when the trial resumes on 21 June.

Wolfe’s estate claims that Page and Plant incorporated a musical phrase from Taurus in the introduction to their 1971 classic.

Anderson said attorney Francis Malofiy had failed to show that members of Led Zeppelin were familiar with the song and experts had not presented a convincing case that the tunes were similar enough to constitute copyright infringement.

Musical experts for the Wolfe estate said there were many similarities between the obscure instrumental Taurus and Stairway, but a defence expert testified on 17 June that the only resemblance was a common descending chord sequence that has been used as a musical building block for 300 years.

Anderson also said the plaintiff failed to show actual damages from any infringement or present evidence of revenues from Stairway to Heaven.

An economist testified that Led Zeppelin works that include the song in question earned almost $60m (£40.7m) in revenues in the last five years, but that included other works and didn’t include manufacturing costs or other expenses.