Pakistani nuclear scientist Abdul Qadeer Khan. — Photo by AP

WASHINGTON: Nuclear scientist Abdul Qadeer Khan said North Korea's government paid more than $3 million in bribes to top Pakistani military officials to obtain nuclear technology, the Washington Post reported on Wednesday.

Khan has released a copy of a letter from a North Korean official dated 1998 which details the deal, the Post said.

The letter says that $3 million was paid to one Pakistani military official, while another was given a half-million dollars and some jewellery. It appears to be signed by North Korean Workers Party Secretary Jon Byong, the newspaper said.

In exchange, Khan was expected to give documents on a nuclear program to North Korea, said the Post, which said it was unable to independently verify the account.

Khan has admitted giving centrifuges and drawings that helped North Korea begin the work of making a uranium-based bomb. It already has nuclear weapons made with plutonium.

But Pakistan has accused Khan of acting alone in giving North Korea access to nuclear secrets.

The Post reported that some Western intelligence officials said they believed the letter was authentic, although Pakistani officials say it is a fake.