Pope Benedict yesterday named Kazimierz Nycz, a bishop with a spotless record, as archbishop of Warsaw to replace a prelate who resigned in disgrace after admitting he spied for the communist police.

Nycz, 57, has been bishop of Koszalin-Kolobrzeg, a city on the Baltic coast, since 2004 and is believed to be totally free of any links with the communist-era secret services in the homeland of the late Pope John Paul.

He replaces Stanislaw Wielgus, who resigned on January 7 during the Mass at which he was to have been invested in his new office. The incident was a major embarrassment for the Vatican and the Polish Church.

On the day he resigned, Wielgus apologised for his actions and admitted he had hurt the Church. He spied on his fellow clerics, many of whom fought against the communist government. During the Cold War, hundreds of thousands of citizens in East bloc countries reported on their neighbours and co-workers.

A recent book disclosing Polish clergy who collaborated with communist-era secret services calls Nycz a totally incorruptible cleric.

The book, Priests and the Security Service, says the secret police gave up on Nycz after years of trying to recruit or find something to blackmail him with.

Nycz, who was in charge of organising the late Pope John Paul's trips to Poland, was under close secret police surveillance from 1978 to 1986, according to the book written by Catholic priest Tadeusz Isakowicz-Zaleski.

The book uses secret police files to paint a picture of Nycz as an ecclesiastical Mr Clean.