"Condolences on the passing of Tunku Abdul Jalil. May his soul be blessed," Najib said in a tweet soon after news broke out of Tunku Jalil's passing.
Tunku Jalil passed away at 7.11pm Saturday at the Royal Ward, Sultanah Aminah Hospital, Johor Baru of cancer. He was 25.
Other Cabinet members who sent condolences via Twitter were Defence Minister Datuk Seri Hishamuddin Hussein, Transport Minister Datuk Seri Liow Tiong Lai and Youth and Sports Minister Khairy Jamaluddin and Minister in the Prime Minister's Department Datuk Seri Dr Wee Ka Siong.
Tengku Puan Pahang Tunku Azizah Maimunah Iskandariah posted a picture of her family with the prince on Instagram with prayers for the prince.
Inspector-General of Police Tan Sri Khalid Abu Bakar said Tunku Jalil, who served several months as a police inspector, was a good policeman.
"On behalf of all those in PDRM, I send my condolence to the Tunku Laksamana Johor. May his soul be with those that are righteous,” Khalid said in a text message.
Tunku Laksamana Johor Tunku Jalil was born in Johor Baru on July 5, 1990 to Sultan Ibrahim and Permaisuri Johor Raja Zarith Sofiah Binti Almarhum Sultan Idris Shah.
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