A woman who claims she is Prince’s half-sister has filed court documents saying she should inherit part of the singer-songwriter’s estate.

Darcell Gresham Johnson, who believes she shares a mother with the music legend, added she is an “interested party and beneficiary” in his assets.

Her legal action will likely add further complications for lawyers attempting to distribute Prince’s assets, which could be worth hundreds of millions of dollars.

It was thought that his estate would be split equally between his six known siblings as he had no children or living parents – and the family has been unable to find a will.

If a court in Minnesota decides Ms Johnson’s claim is legitimate, the estate could end up being divided seven ways.

TMZ has reported that some of Prince’s siblings only became aware of her existence a few days ago.

Prince died suddenly on 21 April aged 57 after being found unresponsive in an elevator at Paisley Park, the expansive complex where he lived and worked.

At a hearing on Monday, Prince’s long-time bank was appointed as the special administrator to handle the star’s estate until an executor is named.

The scrum of lawyers and journalists appeared to surprise the judge overseeing the proceedings, who said: “We’re not used to this much notoriety in Carver County.”

Legal experts say it will take a long time to settle the estate, with Judith Younger, a law professor at the University of Minnesota, saying “it is a real mess he left behind”.

She has expressed surprise that there may not be a will at all, especially given how protective Prince was over his business and music interests.

Meanwhile, detectives are looking into whether Prince was being prescribed drugs by a doctor in the weeks before his death – and whether the star died of an overdose.

A powerful painkiller such as Percocet may have been involved, according to anonymous law enforcement officials.

Prince’s personal chef has said the singer spent his final months battling sore throats and stomach pains for “weeks at a time”.