Russia’s space officials are rushing to find a replacement for British singer Sarah Brightman after she pulled out as the next space tourist four months before her planned trip.

The singer known for roles in West End musicals such as Phantom of the Opera said on Wednesday she was suspending her plans to fly to the International Space Station for family reasons, reportedly her mother’s poor health.

Brightman, 54, had paid $64 million to fly to the ISS, and hoped to become the first soprano to sing on board. She underwent training and passed health checks.

• Got a dirty job? Let the internet take care of it
• Why a high Australian dollar is bad news for you

Speculation in Russia centred on whether Brightman pulled out because of safety fears after an unmanned supply ship to the ISS lost contact with mission control after its launch last month and fell back to Earth.

Brightman wanted to fly “on condition of complete safety – she didn’t want to risk a hair,” Igor Marinin, editor of Space News magazine, told RIA Novosti news agency.

Astronauts on the ISS are spending an extra month aboard while Russia investigates the accident.

The next space launch has also been delayed although this was not expected to affect the September 1 flight.

Reports also questioned whether Brightman had failed to raise funds.

The Izvestia daily cited an “informed source” as saying: “As far as we know from our partners, the main reason is that the singer could not attract a big enough sum from sponsors to cover her ISS trip.”

The singer has said she is paying for the trip herself.

“Several candidates are now being looked at to replace Sarah Brightman,” a source in the space industry told Interfax news agency.

“The chances of finding a suitable candidate are small, especially since there’s practically no time left for training.”