The sale of six previously unreleased Prince songs — scheduled to coincide with the first anniversary on Friday of the singer’s death by accidental overdose — has been halted by a judge.

On Tuesday, Prince’s estate sued the producer and recording engineer behind the project, George Ian Boxill, claiming that he was not authorized to sell the compositions and had violated a confidentiality agreement he made with the musician while the pair worked together between 2006 and 2008. Mr. Boxill had planned to release the six songs as an EP, “Deliverance,” to digital retailers this week via an independent label, RMA (Rogue Music Alliance), despite the estate’s wide-ranging agreement with the Universal Music Group for control over Prince’s later-career work.

At a hearing on Wednesday evening in Minnesota, Judge Wilhelmina M. Wright of the United States District Court sided with the estate, issuing a temporary restraining order blocking the dissemination of Prince’s music by Mr. Boxill and ordering him to “deliver all of the recordings acquired through his work with Paisley Park Enterprises, including original recordings, analog and digital copies” to the estate. The order expires on May 3 unless it is extended by the court.

Streaming services and retailers, including iTunes, Amazon and SoundCloud, have pulled the pre-order option for the EP, as well as the song “Deliverance,” which was released early. For a time, the track remained available for purchase via princerogersnelson.com, a website credited to RMA, which had been selling the six songs in full on Wednesday. But the site later appeared to be inactive.