WASHINGTON 

A death row inmate in Missouri who has long claimed his innocence and faces being put to death in under a week petitioned the US Supreme Court on Wednesday for a stay of execution, according to a report.   

Marcellus Williams, 55, was convicted of first-degree murder in 2001 for the 1998 stabbing death of Felicia Gayle, a former newspaper reporter.

His execution is scheduled for Sept. 24, despite ongoing legal battles and claims of due process violations, CNN reported.

Citing court documents, it said that Williams’ legal team pointed to a decision by former Missouri Governor Eric Greitens, who halted Williams’ execution indefinitely and formed a special board to investigate the case and consider clemency.

"The Board investigated Williams’ case for the next six years — until (Missouri) Governor Michael Parson abruptly terminated the process," CNN quoted his lawyers as saying.

“The governor’s actions have violated Williams’ constitutional rights and created an exceptionally urgent need for the Court’s attention,” it also cites the court documents as saying.

The St. Louis County Prosecuting Attorney's Office plans to appeal a judge's decision affirming Williams’ conviction and death sentence to the Missouri Supreme Court, according to reports.

The National Association for the Advancement of Colored People (NAACP) is also urging Governor Parson to stop the execution of Williams, highlighting that the death penalty has been “historically applied with racial bias,” especially in Missouri.

The relatives of the murder victim are also reportedly against Williams' execution.