The US supreme court has stayed the first scheduled execution of a Texas death-row inmate using pentobarbital.

Cleve Foster was to have been executed on Tuesday evening for the 2002 murder of a Sudanese woman in Fort Worth – the first Texas execution since the state switched to pentobarbital in its lethal three-drug mixture.

On Tuesday morning, the court agreed to reconsider its earlier order denying Foster's appeal that had raised claims of innocence and poor legal help during his trial and the early stages of his appeals.

Foster's lawyers have argued that Texas prison officials violated administrative procedures last month when they announced the switch to pentobarbital from sodium thiopental, which is in short supply nationwide. They contend that the rule change required more time for public comment and review.

Lower courts have rejected their appeals and they had planned to take their case to the Texas supreme court. At the same time, they sought a rehearing before the US supreme court over its rejection of an appeal in January. The court had stopped Foster's then-scheduled execution, but its rejection of his claims a week later cleared the way for Tarrant county authorities to schedule the execution for Tuesday.

In its brief ruling, the court gave prosecutors 30 days to respond to the defence petition, after which the supreme court will decide if the appeal has merit.

The issue over the execution drug was not before the court and the order on Tuesday did not mention it.

The drug swap is the most significant change in the execution procedure in Texas since the state switched from the electric chair to lethal injection when it reinstated capital punishment in 1982. Pentobarbital is a sedative used in surgery and to euthanise animals, and has already been used for executions in Oklahoma and Ohio.