The announcement was made on Monday by the state of California that Östberg Deasy would, after more than 27 years in a US prison, be returned to Sweden to complete her sentence.

“She has been released from the prison after an agreement with the Swedish government. She will be transferred to Sweden,” a spokesperson said.

The media was later informed that the transfer had been made last week.

“Inmate Deasy was released from the California Institution for Women and transferred to the federal authorities on March 25th 2009,” Terry Thornton at the California prison authority confirmed.

The Swedish authorities in the US are being reticent with the details of Östberg Deasy’s transfer.

“We have no comment at all on the information,” Cecilia Julin at the Swedish foreign ministry in Stockholm said.

According to reports in the Expressen newspaper Östberg Deasy spent last night in the Metropolitan Correctional Center in New York.

Östberg Deasy will be flown home to Sweden on Tuesday in a private chartered jet that will cost the Swedish prisons service at least 500,000 kronor ($62,000).

Annika Östberg Deasy, now 55, moved to California with her mother in the 1960s. As a teenager she experienced serious drug problems and ran away from home.

She later started a relationship with a drug dealer, Brian Cox. In April 1981, the couple argued with restaurant owner, Joe Torre, over money. Cox shot Torre dead.

The following day, Cox and Östberg’s car got a puncture and policeman Richard Helbush pulled over to help them. Thinking they were about to be arrested, Cox shot Helbush dead as well.

The couple fled in the police car and were later arrested after a police pursuit and a gunfight. Cox hanged himself in his cell prior to the trial.