ISLAMABAD — Nuclear scientist Dr. Abdul Qadeer Khan passed away in Islamabad on Sunday morning at the age of 85, the Dawn newspaper reported.

According to Radio Pakistan, he was admitted to a local hospital where his health deteriorated early morning. PTV said that he died after being transferred to a hospital with lung problems.

Interior Minister Sheikh Rashid Ahmed said that under the directions issued by Prime Minister Imran Khan, Dr. Khan would be given a state funeral.

He said that the funeral prayers would be held at Faisal Mosque at 3:30 p.m. "The general public will be allowed to attend," he said.

"The whole nation is grieving," the minister said, adding that the flag would be flown at half-mast.

Prime Minister Imran Khan said Dr. Khan was loved by the nation because of his critical contribution in making Pakistan a nuclear weapon state.

"This has provided us security against an aggressive much larger nuclear neighbor. For the people of Pakistan he was a national icon," he said, adding that he would be buried in Faisal Mosque "as per his wishes".

President Dr. Arif Alvi said that he had personally known Dr. Khan since 1982. "He helped us develop nation-saving nuclear deterrence, and a grateful nation will never forget his services in this regard," he said.

Last month, Dr. Khan had complained that neither PM Imran nor any of his Cabinet members inquired after his health while he was under treatment at a hospital.

According to the state-run Associated Press of Pakistan, Dr. Khan had been admitted to Khan Research Laboratories Hospital on Aug. 26 after he tested positive for COVID-19.

Later, he was shifted to a military hospital in Rawalpindi but was discharged after recovering from the virus.

According to a statement issued by the Inter-Services Public Relations (ISPR), Chairman Joint Chiefs of Staff Committee Gen. Nadeem Raza and all services chiefs expressed sorrow over Dr. Khan's passing.

The ISPR statement also quoted Chief of Army Staff Gen. Qamar Javed Bajwa as saying that he had rendered invaluable services to strengthen Pakistan's defense capabilities.

Leader of the opposition in the National Assembly Shehbaz Sharif said that the nation had lost "a true benefactor who served the motherland with heart and soul."

"The passing of Dr. Khan is a huge loss for the country. His role in making Pakistan an atomic power remains central," he said.

Defense Minister Pervez Khattak said he was "deeply grieved" over his passing and called it a "great loss".

Born in 1936 in Bhopal, India, Dr. Khan had immigrated along with his family to Pakistan in 1947 after partition of the subcontinent.

He did a science degree at Karachi University in 1960, then went on to study metallurgical engineering in Berlin before completing advanced studies in the Netherlands and Belgium.

Known as AQ Khan, the scientist was instrumental in setting up Pakistan's first nuclear enrichment plant at Kahuta near Islamabad. By 1998, the country had conducted its first nuclear tests.

Coming shortly after similar tests by India, Dr Khan's work helped seal Pakistan's place as the world's seventh nuclear power and sparked national jubilation.

He was awarded the Nishan-i-Imtiaz for his services to the country.

In 2004, Dr. Khan was at the center of a massive global nuclear proliferation scandal. In a series of dramatic developments, he was accused by then army chief and president Pervez Musharraf of running a rogue proliferation network for nuclear material.

Shortly after Musharraf’s announcement, a recorded confession by Khan was aired in which he took sole responsibility for all the nuclear proliferation that had been revealed. He was subsequently placed under house arrest. A court ended his house arrest in February 2009, but his movements were restricted. — Dawn/BBC