"Harry Potter And The Cursed Child", a stage adaptation of J.K Rowling's fantastical world of witches and wizards, cast a magical spell at the Olivier Awards on Sunday, scooping nine wins at Britain's big night for theatre.

The critically-acclaimed production, which opened last year in London's West End, went in with 11 nominations. Its victorious haul made it "the most decorated production in the ceremony's history", awards organisers said.

The eighth story in the "Harry Potter" series, the play follows Rowling's young boy wizard and friends Ron and Hermione into adulthood. It took best new play, best actor, best actor and actress in a supporting role as well as best director.

"The power of imagination is infinite," director John Tiffany said in his acceptance speech. "We need it now more than ever."

Jamie Parker, who portrays the older Harry, won best actor, beating off competition from the likes of Ian McKellen and Ed Harris. Anthony Boyle, who plays Scorpius Malfoy, took best actor in a supporting role while best actress in a supporting role went to Noma Dumezweni, who plays an adult Hermione.

"Thank you J.K. Rowling for creating Hermione and...the privilege of being able to play Hermione is overwhelming and humbling," Dumezweni said.

The play also won best lighting design, best sound design, best costume design and best set design.

Other winners at the glitzy ceremony at London's Royal Albert Hall included children playing instruments in "School of Rock", composer Andrew Lloyd Webber's adaptation of the 2003 comedy film, who won in the outstanding achievement in music category.

"Groundhog Day", an adaptation of the famed 1993 film starring Bill Murray, won best new musical as well as best actor in a musical for Andy Karl.

"Glee" actress Amber Riley scooped the best actress in a musical award for "Dreamgirls" while fellow cast member Adam J Bernard won best actor in a supporting role in a musical.

Billie Piper won best actress for "Yerma", an adaptation of the play by Federico Garcia Lorca, which won best revival.

"Jesus Christ Superstar" won best musical revival. "Our ladies of Perpetual Succour" won best new comedy while "Akhnaten" took the prize for best new opera production.

Actor and director Kenneth Branagh was honoured with the Special Award in recognition of his "outstanding contribution to British theatre".

Performances on the night included songs from musicals "The Girls", "Dreamgirls" and "School of Rock".