PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - Malaysia's former prime minister Najib Razak's arrest on his wife's birthday has prompted his daughter to pen an emotional heartfelt post on Instagram.

"I know today is not the easiest day for us but let's take a moment to thank Allah that we are all healthy, alive and still able to help others in need," said Ms Nooryana Najwa.

Together with the message, Ms Nooryana had also posted a photo of her mother, Rosmah Mansor, carrying her when she was a child.

"Happy Birthday to my one and only Mummy. Love will get us through it all," she said on her Instagram account on Monday (Dec 10).

Rosmah turns 67 on Monday.

Ms Nooryana had posted the message following Najib's arrest by graft investigators over the "tampering" of the 1MDB final audit report.

Najib was arrested at around 11am at the Malaysian Anti-Corruption Commission headquarters here, minutes after he arrived for a fresh round of questioning over the issue.