KUALA LUMPUR, June 16 — The Prime Minister’s principal private secretary Datuk Marzuki Mohamad has directed all civil servants to use Prime Minister Tan Sri Muhyiddin Yassin’s official name in formal documents with immediate effect.

The circular dated June 3 said the Attorney General’s Chambers has advised that all formal documents bearing the prime minister’s name must identify him as Mahiaddin Md Yasin or Tan Sri Dato Haji Mahiaddin Md Yasin.

Mahiaddin is the prime minister’s given name, but he is better known through his adopted name of Muhyiddin.

The circular appeared to be motivated by a High Court ruling in April that revoked a detention order the prime minister had signed, on grounds that it carried his unofficial name.

The judge ruled that under the Ministerial Functions Act 1969, the prime minister must use his gazetted name of Mahiaddin Md Yasin as that was the one stated in his MyKad.