A Japanese daily says North Korea has recently reinstated a former top official who was under house arrest on charges of dissident activities.

The Tokyo Shimbun on Monday said Jang Seong-taek, brother-in-law of North Korean leader Kim Jong-il and formerly a leading official in the Workers' Party, has apparently returned to a key post of the party's leadership.

The news comes amid growing global pressure on the North's nuclear ambition.

The report said Kim probably seeks to solidify his power base by reinstating Jang, one of his few relatives and once regarded as the number two man in the country.

Jang is also known to have close ties with Kim's eldest son Jong-nam, a relationship which may affect the change of power in the North.