MUSCAT, Sept 28 (Reuters) - Police in Oman have detained a senior judge who criticized the judiciary in a newspaper which was shut down earlier this week by court order, an Omani rights group said on Wednesday.

Ali al-Numani, Oman's supreme court deputy, is being held in a police hospital and is in good health, the Omani Human Rights Commission said in a statement.

Numani told the privately owned Azamn newspaper in an interview in August that Oman's attorney general and supreme court justice chief had "abused laws of the state".

He also apologized for the way authorities treated the newspaper, which had reported extensively on a series of corruption cases in 2014 in which several company executives were convicted.

An Omani court on Monday ordered the permanent closure of Azamn and jailed three of its journalists on charges that included undermining the prestige of the state.

A police spokesperson declined to comment on the detention of Numani.

A State Department spokesman said on Monday the United States was very concerned about the court decisions and the U.S. ambassador had conveyed the concern to Oman's government at a senior level.

(Reporting by Fatma Al Arimi; Writing by Tom Finn; Editing by Dominic Evans) ((Tom.Finn@thomsonreuters.com;))