Richey was sentenced to death more than 20 years ago after being convicted of deliberately starting a fire in which a two-year-old girl died.

The grounds of appeal were that Richey, originally from Edinburgh, received inadequate legal representation during his trial in 1987. However, prosecutors are likely to appeal against the latest decision.

The appeal was decided by the United States Court of Appeal for the Sixth Circuit, the second highest court that can hear the case. The court ordered that Richey should be retried or released within 90 days.

In January 2005, the same court overturned Richey's conviction and announced that he should be retried or released. However, the prosecution appealed. The US Supreme Court held that the decision to overturn his conviction may not have been procedurally correct and so asked the Court of Appeals of the Sixth Circuit to reconsider.

This was in November 2005 and Richey has remained on death row until Friday's decision. Richey has always denied murdering his former girlfriend's two-year-old daughter, Cynthia Collins. He was found guilty of starting a fire at the toddler's mother's apartment in the town of Columbus Grove in 1986.