KARACHI — Pakistan's anti-graft agency said on Wednesday it had arrested opposition Pakistan People's Party leader Khursheed Shah in an investigation into the sources of his wealth, the latest high-profile detention of an opposition politician.

The National Accountability Bureau (NAB) said that Shah was arrested in relation to allegations of his assets being higher than his known sources of income.

"NAB's Sukkur chapter has arrested Syed Khursheed Shah over 'assets beyond means'," the NAB said in a statement, adding that he would appear in an anti-corruption court in the southeastern city of Sukkur.

Both major opposition parties, including Shah's PPP, condemned the arrest, which they said was a case of "political victimization", an accusation the government denies.

"We condemn it. It is beyond understanding," PPP senator Murtaza Wahab told local Geo TV.

The government said that it had nothing to do with the NAB's operations and the corruption body was simply carrying out its job.

"NAB is an independent institution," said government minister Ali Zaidi.

The anti-graft agency has arrested, or wants to arrest, about a dozen members of the Sharif family, which runs the largest opposition party, the Pakistan Muslim League-Nawaz (PML-N).

In August, NAB arrested Maryam Nawaz, a high profile member of the Sharif political dynasty and leader of PML-N. Prime Minister Imran Khan and Pakistan's powerful military deny that the cases against the family are politically motivated. — Reuters