A spokesperson for the anti-graft watchdog said the meeting of Ahad Cheema with his wife lasted for one hour and they were not interrupted during the meeting.
He said the bureau had been working in accordance with the NAB laws, adding that the bureaucrat was in good health.
Last week, the anti-corruption watchdog arrested Cheema, former Director General (DG) Lahore Development Authority (LDA), drawing sharp reaction from a section of the Punjab bureaucracy and PML-N leaders.
Cheema, who is now serving as chief executive of the Punjab Power Company, was arrested from his office located in Gulbarg area of Lahore.
The former LDA chief has been accused of misusing his authority with criminal intent to award a contract to Bismillah Engineering on the basis of nepotism.
The anti-graft body spokesperson alleged that Cheema caused a loss of Rs 455 million to the national exchequer after awarding contracts on the basis of favouritism.
On Friday, the NAB investigators obtained access to mobile and laptop data of Cheema to investigate the data and emails. It was then said that the investigators would also approach technical experts to secure and restore the data which had been either formatted or deleted.